The Swift Package Index logo.Swift Package Index

Track the adoption of Swift 6 strict concurrency checks for data race safety. How many packages are Ready for Swift 6?

Build Information

Failed to build Music, reference 0.17.1 (f3fd48), with Swift 6.0 for Linux on 1 Nov 2024 03:39:48 UTC.

Build Command

bash -c docker run --pull=always --rm -v "checkouts-4606859-0":/host -w "$PWD" registry.gitlab.com/finestructure/spi-images:basic-6.0-latest swift build --triple x86_64-unknown-linux-gnu -Xswiftc -Xfrontend -Xswiftc -stats-output-dir -Xswiftc -Xfrontend -Xswiftc .stats -Xswiftc -strict-concurrency=complete 2>&1

Build Log

   |                        `- note: candidate exactly matches
80 |         lhs = lhs - rhs
81 |     }
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:111:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
109 |
110 |     /// Unison.
111 |     public static let unison = CompoundIntervalDescriptor(.unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
112 |
113 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:47:23: warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
 45 |
 46 |     /// The `unison` is the `zero` for the `CompoundIntervalDescriptor` `AdditiveGroup`.
 47 |     public static let zero: CompoundIntervalDescriptor = .unison
    |                       |- warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'zero' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 48 |
 49 |     /// **Example Usage:**
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:178:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
176 |
177 |     /// Unison.
178 |     public static let unison = OrderedIntervalDescriptor(.perfect, .unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
179 |
180 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:114:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
112 |
113 |     /// Minor second.
114 |     public static let m2 = CompoundIntervalDescriptor(.m2)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
115 |
116 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:181:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
179 |
180 |     /// Minor second.
181 |     public static let m2 = OrderedIntervalDescriptor(.minor, .second)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
182 |
183 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:117:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
115 |
116 |     /// Major second.
117 |     public static let M2 = CompoundIntervalDescriptor(.M2)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
118 |
119 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:184:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
182 |
183 |     /// Major second.
184 |     public static let M2 = OrderedIntervalDescriptor(.major, .second)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
185 |
186 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:120:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
118 |
119 |     /// Minor third.
120 |     public static let m3 = CompoundIntervalDescriptor(.m3)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
121 |
122 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:187:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
185 |
186 |     /// Minor third.
187 |     public static let m3 = OrderedIntervalDescriptor(.minor, .third)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
188 |
189 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:123:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
121 |
122 |     /// Major third.
123 |     public static let M3 = CompoundIntervalDescriptor(.M3)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
124 |
125 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:190:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
188 |
189 |     /// Major third.
190 |     public static let M3 = OrderedIntervalDescriptor(.major, .third)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
191 |
192 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:126:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
124 |
125 |     /// Diminished fourth.
126 |     public static let d4 = CompoundIntervalDescriptor(.d4)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
127 |
128 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:193:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
191 |
192 |     /// Diminished fourth.
193 |     public static let d4 = OrderedIntervalDescriptor(.diminished, .fourth)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
194 |
195 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:129:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
127 |
128 |     /// Perfect fourth.
129 |     public static let P4 = CompoundIntervalDescriptor(.P4)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
130 |
131 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:196:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
194 |
195 |     /// Perfect fourth.
196 |     public static let P4 = OrderedIntervalDescriptor(.perfect, .fourth)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
197 |
198 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:132:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
130 |
131 |     /// Augmented fourth.
132 |     public static let A4 = CompoundIntervalDescriptor(.A4)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
133 |
134 |     /// Diminished fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:202:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
200 |
201 |     /// Augmented fourth.
202 |     public static let A4 = OrderedIntervalDescriptor(.augmented, .fourth)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
203 |
204 |     /// Diminished fifth
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:135:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
133 |
134 |     /// Diminished fifth.
135 |     public static let d5 = CompoundIntervalDescriptor(.d5)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
136 |
137 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:205:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
203 |
204 |     /// Diminished fifth
205 |     public static let d5 = OrderedIntervalDescriptor(.diminished, .fifth)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
206 |
207 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:138:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
136 |
137 |     /// Perfect fifth.
138 |     public static let P5 = CompoundIntervalDescriptor(.P5)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
139 |
140 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:199:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
197 |
198 |     /// Perfect fifth.
199 |     public static let P5 = OrderedIntervalDescriptor(.perfect, .fifth)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
200 |
201 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:141:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
139 |
140 |     /// Augmented fifth.
141 |     public static let A5 = CompoundIntervalDescriptor(.A5)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
142 |
143 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:208:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
206 |
207 |     /// Augmented fifth.
208 |     public static let A5 = OrderedIntervalDescriptor(.augmented, .fifth)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
209 |
210 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:144:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
142 |
143 |     /// Minor sixth.
144 |     public static let m6 = CompoundIntervalDescriptor(.m6)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
145 |
146 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:211:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
209 |
210 |     /// Minor sixth.
211 |     public static let m6 = OrderedIntervalDescriptor(.minor, .sixth)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
212 |
213 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:147:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
145 |
146 |     /// Major sixth.
147 |     public static let M6 = CompoundIntervalDescriptor(.M6)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
148 |
149 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:214:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
212 |
213 |     /// Major sixth.
214 |     public static let M6 = OrderedIntervalDescriptor(.major, .sixth)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
215 |
216 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:150:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
148 |
149 |     /// Minor seventh.
150 |     public static let m7 = CompoundIntervalDescriptor(.m7)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
151 |
152 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:217:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
215 |
216 |     /// Minor seventh.
217 |     public static let m7 = OrderedIntervalDescriptor(.minor, .seventh)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
218 |
219 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:153:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
151 |
152 |     /// Major seventh.
153 |     public static let M7 = CompoundIntervalDescriptor(.M7)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
154 |
155 |     /// Octave.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:220:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
218 |
219 |     /// Major seventh.
220 |     public static let M7 = OrderedIntervalDescriptor(.major, .seventh)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
221 |
222 |     // TODO: Add diminished / augmented imperfect intervals
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:156:23: warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
154 |
155 |     /// Octave.
156 |     public static let octave = CompoundIntervalDescriptor(.unison, displacedBy: 1)
    |                       |- warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octave' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
157 |
158 |     // TODO: Add intervals spanning more than one octave
[159/172] Compiling Pitch Frequency.swift
/host/spi-builder-workspace/Sources/Pitch/Frequency.swift:25:15: error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
23 | ///     let mean: Frequency = 440.0 // => "a 440"
24 | ///
25 | public struct Frequency: NewType, SignedNumeric {
   |               `- error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
26 |
27 |     // MARK: - Instance Properties
Swift.AdditiveArithmetic:4:17: note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
2 |     static var zero: Self { get }
3 |     static func + (lhs: Self, rhs: Self) -> Self
4 |     static func += (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
5 |     static func - (lhs: Self, rhs: Self) -> Self
6 |     static func -= (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '-=' with type '(inout Frequency, Frequency) -> ()'
7 | }
Swift.AdditiveArithmetic:2:24: note: candidate exactly matches
1 | extension AdditiveArithmetic {
2 |     public static func += (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
3 |     public static func -= (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
4 | }
/host/spi-builder-workspace/.build/checkouts/Structure/Sources/DataStructures/Wrapping/NewType.swift:71:24: note: candidate exactly matches
69 |     }
70 |
71 |     public static func += (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
72 |         lhs = lhs + rhs
73 |     }
   :
77 |     }
78 |
79 |     public static func -= (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
80 |         lhs = lhs - rhs
81 |     }
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:111:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
109 |
110 |     /// Unison.
111 |     public static let unison = CompoundIntervalDescriptor(.unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
112 |
113 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:47:23: warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
 45 |
 46 |     /// The `unison` is the `zero` for the `CompoundIntervalDescriptor` `AdditiveGroup`.
 47 |     public static let zero: CompoundIntervalDescriptor = .unison
    |                       |- warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'zero' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 48 |
 49 |     /// **Example Usage:**
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:178:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
176 |
177 |     /// Unison.
178 |     public static let unison = OrderedIntervalDescriptor(.perfect, .unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
179 |
180 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:114:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
112 |
113 |     /// Minor second.
114 |     public static let m2 = CompoundIntervalDescriptor(.m2)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
115 |
116 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:181:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
179 |
180 |     /// Minor second.
181 |     public static let m2 = OrderedIntervalDescriptor(.minor, .second)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
182 |
183 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:117:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
115 |
116 |     /// Major second.
117 |     public static let M2 = CompoundIntervalDescriptor(.M2)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
118 |
119 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:184:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
182 |
183 |     /// Major second.
184 |     public static let M2 = OrderedIntervalDescriptor(.major, .second)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
185 |
186 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:120:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
118 |
119 |     /// Minor third.
120 |     public static let m3 = CompoundIntervalDescriptor(.m3)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
121 |
122 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:187:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
185 |
186 |     /// Minor third.
187 |     public static let m3 = OrderedIntervalDescriptor(.minor, .third)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
188 |
189 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:123:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
121 |
122 |     /// Major third.
123 |     public static let M3 = CompoundIntervalDescriptor(.M3)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
124 |
125 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:190:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
188 |
189 |     /// Major third.
190 |     public static let M3 = OrderedIntervalDescriptor(.major, .third)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
191 |
192 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:126:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
124 |
125 |     /// Diminished fourth.
126 |     public static let d4 = CompoundIntervalDescriptor(.d4)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
127 |
128 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:193:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
191 |
192 |     /// Diminished fourth.
193 |     public static let d4 = OrderedIntervalDescriptor(.diminished, .fourth)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
194 |
195 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:129:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
127 |
128 |     /// Perfect fourth.
129 |     public static let P4 = CompoundIntervalDescriptor(.P4)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
130 |
131 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:196:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
194 |
195 |     /// Perfect fourth.
196 |     public static let P4 = OrderedIntervalDescriptor(.perfect, .fourth)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
197 |
198 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:132:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
130 |
131 |     /// Augmented fourth.
132 |     public static let A4 = CompoundIntervalDescriptor(.A4)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
133 |
134 |     /// Diminished fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:202:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
200 |
201 |     /// Augmented fourth.
202 |     public static let A4 = OrderedIntervalDescriptor(.augmented, .fourth)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
203 |
204 |     /// Diminished fifth
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:135:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
133 |
134 |     /// Diminished fifth.
135 |     public static let d5 = CompoundIntervalDescriptor(.d5)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
136 |
137 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:205:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
203 |
204 |     /// Diminished fifth
205 |     public static let d5 = OrderedIntervalDescriptor(.diminished, .fifth)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
206 |
207 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:138:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
136 |
137 |     /// Perfect fifth.
138 |     public static let P5 = CompoundIntervalDescriptor(.P5)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
139 |
140 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:199:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
197 |
198 |     /// Perfect fifth.
199 |     public static let P5 = OrderedIntervalDescriptor(.perfect, .fifth)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
200 |
201 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:141:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
139 |
140 |     /// Augmented fifth.
141 |     public static let A5 = CompoundIntervalDescriptor(.A5)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
142 |
143 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:208:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
206 |
207 |     /// Augmented fifth.
208 |     public static let A5 = OrderedIntervalDescriptor(.augmented, .fifth)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
209 |
210 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:144:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
142 |
143 |     /// Minor sixth.
144 |     public static let m6 = CompoundIntervalDescriptor(.m6)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
145 |
146 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:211:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
209 |
210 |     /// Minor sixth.
211 |     public static let m6 = OrderedIntervalDescriptor(.minor, .sixth)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
212 |
213 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:147:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
145 |
146 |     /// Major sixth.
147 |     public static let M6 = CompoundIntervalDescriptor(.M6)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
148 |
149 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:214:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
212 |
213 |     /// Major sixth.
214 |     public static let M6 = OrderedIntervalDescriptor(.major, .sixth)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
215 |
216 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:150:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
148 |
149 |     /// Minor seventh.
150 |     public static let m7 = CompoundIntervalDescriptor(.m7)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
151 |
152 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:217:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
215 |
216 |     /// Minor seventh.
217 |     public static let m7 = OrderedIntervalDescriptor(.minor, .seventh)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
218 |
219 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:153:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
151 |
152 |     /// Major seventh.
153 |     public static let M7 = CompoundIntervalDescriptor(.M7)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
154 |
155 |     /// Octave.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:220:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
218 |
219 |     /// Major seventh.
220 |     public static let M7 = OrderedIntervalDescriptor(.major, .seventh)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
221 |
222 |     // TODO: Add diminished / augmented imperfect intervals
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:156:23: warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
154 |
155 |     /// Octave.
156 |     public static let octave = CompoundIntervalDescriptor(.unison, displacedBy: 1)
    |                       |- warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octave' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
157 |
158 |     // TODO: Add intervals spanning more than one octave
[160/172] Compiling Pitch CompoundIntervalDescriptor.swift
/host/spi-builder-workspace/Sources/Pitch/Frequency.swift:25:15: error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
23 | ///     let mean: Frequency = 440.0 // => "a 440"
24 | ///
25 | public struct Frequency: NewType, SignedNumeric {
   |               `- error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
26 |
27 |     // MARK: - Instance Properties
Swift.AdditiveArithmetic:4:17: note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
2 |     static var zero: Self { get }
3 |     static func + (lhs: Self, rhs: Self) -> Self
4 |     static func += (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
5 |     static func - (lhs: Self, rhs: Self) -> Self
6 |     static func -= (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '-=' with type '(inout Frequency, Frequency) -> ()'
7 | }
Swift.AdditiveArithmetic:2:24: note: candidate exactly matches
1 | extension AdditiveArithmetic {
2 |     public static func += (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
3 |     public static func -= (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
4 | }
/host/spi-builder-workspace/.build/checkouts/Structure/Sources/DataStructures/Wrapping/NewType.swift:71:24: note: candidate exactly matches
69 |     }
70 |
71 |     public static func += (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
72 |         lhs = lhs + rhs
73 |     }
   :
77 |     }
78 |
79 |     public static func -= (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
80 |         lhs = lhs - rhs
81 |     }
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:111:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
109 |
110 |     /// Unison.
111 |     public static let unison = CompoundIntervalDescriptor(.unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
112 |
113 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:47:23: warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
 45 |
 46 |     /// The `unison` is the `zero` for the `CompoundIntervalDescriptor` `AdditiveGroup`.
 47 |     public static let zero: CompoundIntervalDescriptor = .unison
    |                       |- warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'zero' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 48 |
 49 |     /// **Example Usage:**
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:178:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
176 |
177 |     /// Unison.
178 |     public static let unison = OrderedIntervalDescriptor(.perfect, .unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
179 |
180 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:114:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
112 |
113 |     /// Minor second.
114 |     public static let m2 = CompoundIntervalDescriptor(.m2)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
115 |
116 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:181:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
179 |
180 |     /// Minor second.
181 |     public static let m2 = OrderedIntervalDescriptor(.minor, .second)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
182 |
183 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:117:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
115 |
116 |     /// Major second.
117 |     public static let M2 = CompoundIntervalDescriptor(.M2)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
118 |
119 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:184:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
182 |
183 |     /// Major second.
184 |     public static let M2 = OrderedIntervalDescriptor(.major, .second)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
185 |
186 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:120:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
118 |
119 |     /// Minor third.
120 |     public static let m3 = CompoundIntervalDescriptor(.m3)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
121 |
122 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:187:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
185 |
186 |     /// Minor third.
187 |     public static let m3 = OrderedIntervalDescriptor(.minor, .third)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
188 |
189 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:123:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
121 |
122 |     /// Major third.
123 |     public static let M3 = CompoundIntervalDescriptor(.M3)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
124 |
125 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:190:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
188 |
189 |     /// Major third.
190 |     public static let M3 = OrderedIntervalDescriptor(.major, .third)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
191 |
192 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:126:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
124 |
125 |     /// Diminished fourth.
126 |     public static let d4 = CompoundIntervalDescriptor(.d4)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
127 |
128 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:193:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
191 |
192 |     /// Diminished fourth.
193 |     public static let d4 = OrderedIntervalDescriptor(.diminished, .fourth)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
194 |
195 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:129:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
127 |
128 |     /// Perfect fourth.
129 |     public static let P4 = CompoundIntervalDescriptor(.P4)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
130 |
131 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:196:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
194 |
195 |     /// Perfect fourth.
196 |     public static let P4 = OrderedIntervalDescriptor(.perfect, .fourth)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
197 |
198 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:132:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
130 |
131 |     /// Augmented fourth.
132 |     public static let A4 = CompoundIntervalDescriptor(.A4)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
133 |
134 |     /// Diminished fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:202:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
200 |
201 |     /// Augmented fourth.
202 |     public static let A4 = OrderedIntervalDescriptor(.augmented, .fourth)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
203 |
204 |     /// Diminished fifth
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:135:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
133 |
134 |     /// Diminished fifth.
135 |     public static let d5 = CompoundIntervalDescriptor(.d5)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
136 |
137 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:205:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
203 |
204 |     /// Diminished fifth
205 |     public static let d5 = OrderedIntervalDescriptor(.diminished, .fifth)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
206 |
207 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:138:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
136 |
137 |     /// Perfect fifth.
138 |     public static let P5 = CompoundIntervalDescriptor(.P5)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
139 |
140 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:199:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
197 |
198 |     /// Perfect fifth.
199 |     public static let P5 = OrderedIntervalDescriptor(.perfect, .fifth)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
200 |
201 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:141:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
139 |
140 |     /// Augmented fifth.
141 |     public static let A5 = CompoundIntervalDescriptor(.A5)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
142 |
143 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:208:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
206 |
207 |     /// Augmented fifth.
208 |     public static let A5 = OrderedIntervalDescriptor(.augmented, .fifth)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
209 |
210 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:144:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
142 |
143 |     /// Minor sixth.
144 |     public static let m6 = CompoundIntervalDescriptor(.m6)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
145 |
146 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:211:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
209 |
210 |     /// Minor sixth.
211 |     public static let m6 = OrderedIntervalDescriptor(.minor, .sixth)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
212 |
213 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:147:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
145 |
146 |     /// Major sixth.
147 |     public static let M6 = CompoundIntervalDescriptor(.M6)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
148 |
149 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:214:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
212 |
213 |     /// Major sixth.
214 |     public static let M6 = OrderedIntervalDescriptor(.major, .sixth)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
215 |
216 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:150:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
148 |
149 |     /// Minor seventh.
150 |     public static let m7 = CompoundIntervalDescriptor(.m7)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
151 |
152 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:217:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
215 |
216 |     /// Minor seventh.
217 |     public static let m7 = OrderedIntervalDescriptor(.minor, .seventh)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
218 |
219 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:153:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
151 |
152 |     /// Major seventh.
153 |     public static let M7 = CompoundIntervalDescriptor(.M7)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
154 |
155 |     /// Octave.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:220:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
218 |
219 |     /// Major seventh.
220 |     public static let M7 = OrderedIntervalDescriptor(.major, .seventh)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
221 |
222 |     // TODO: Add diminished / augmented imperfect intervals
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:156:23: warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
154 |
155 |     /// Octave.
156 |     public static let octave = CompoundIntervalDescriptor(.unison, displacedBy: 1)
    |                       |- warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octave' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
157 |
158 |     // TODO: Add intervals spanning more than one octave
error: emit-module command failed with exit code 1 (use -v to see invocation)
[161/172] Emitting module Pitch
/host/spi-builder-workspace/Sources/Pitch/Chord/Chord.IntervalPattern.swift:38:16: warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'Chord.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
13 |
14 |     /// The pattern of intervals which defines the quality of a `Chord`.
15 |     public struct IntervalPattern {
   |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
16 |
17 |         // MARK: - Instance Properties
   :
36 |
37 |     /// Major chord interval pattern.
38 |     static let major: Chord.IntervalPattern = [4,3]
   |                |- warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'Chord.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
   |                |- note: annotate 'major' with '@MainActor' if property should only be accessed from the main actor
   |                `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
39 |
40 |     /// Minor chord interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Chord/Chord.IntervalPattern.swift:41:16: warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'Chord.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
13 |
14 |     /// The pattern of intervals which defines the quality of a `Chord`.
15 |     public struct IntervalPattern {
   |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
16 |
17 |         // MARK: - Instance Properties
   :
39 |
40 |     /// Minor chord interval pattern.
41 |     static let minor: Chord.IntervalPattern = [3,4]
   |                |- warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'Chord.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
   |                |- note: annotate 'minor' with '@MainActor' if property should only be accessed from the main actor
   |                `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
42 |
43 |     // TODO: Add more helpers
/host/spi-builder-workspace/Sources/Pitch/Chord/ChordDescriptor.swift:60:23: warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 18 | ///     let augmented: ChordDescriptor = [.M3, .M3]
 19 | ///
 20 | public struct ChordDescriptor {
    |               `- note: consider making struct 'ChordDescriptor' conform to the 'Sendable' protocol
 21 |
 22 |     // MARK: - Instance Properties
    :
 58 |     // MARK: - Type Properties
 59 |
 60 |     public static let major: ChordDescriptor = [.M3, .m3]
    |                       |- warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'major' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 61 |     public static let minor: ChordDescriptor = [.m3, .M3]
 62 |     public static let diminished: ChordDescriptor = [.m3, .m3]
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:123:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
121 |
122 |     /// Major third.
123 |     public static let M3 = CompoundIntervalDescriptor(.M3)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
124 |
125 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:120:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
118 |
119 |     /// Minor third.
120 |     public static let m3 = CompoundIntervalDescriptor(.m3)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
121 |
122 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/Chord/ChordDescriptor.swift:61:23: warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 18 | ///     let augmented: ChordDescriptor = [.M3, .M3]
 19 | ///
 20 | public struct ChordDescriptor {
    |               `- note: consider making struct 'ChordDescriptor' conform to the 'Sendable' protocol
 21 |
 22 |     // MARK: - Instance Properties
    :
 59 |
 60 |     public static let major: ChordDescriptor = [.M3, .m3]
 61 |     public static let minor: ChordDescriptor = [.m3, .M3]
    |                       |- warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'minor' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 62 |     public static let diminished: ChordDescriptor = [.m3, .m3]
 63 |     public static let augmented: ChordDescriptor = [.M3, .M3]
/host/spi-builder-workspace/Sources/Pitch/Chord/ChordDescriptor.swift:62:23: warning: static property 'diminished' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 18 | ///     let augmented: ChordDescriptor = [.M3, .M3]
 19 | ///
 20 | public struct ChordDescriptor {
    |               `- note: consider making struct 'ChordDescriptor' conform to the 'Sendable' protocol
 21 |
 22 |     // MARK: - Instance Properties
    :
 60 |     public static let major: ChordDescriptor = [.M3, .m3]
 61 |     public static let minor: ChordDescriptor = [.m3, .M3]
 62 |     public static let diminished: ChordDescriptor = [.m3, .m3]
    |                       |- warning: static property 'diminished' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'diminished' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 63 |     public static let augmented: ChordDescriptor = [.M3, .M3]
 64 | }
/host/spi-builder-workspace/Sources/Pitch/Chord/ChordDescriptor.swift:63:23: warning: static property 'augmented' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 18 | ///     let augmented: ChordDescriptor = [.M3, .M3]
 19 | ///
 20 | public struct ChordDescriptor {
    |               `- note: consider making struct 'ChordDescriptor' conform to the 'Sendable' protocol
 21 |
 22 |     // MARK: - Instance Properties
    :
 61 |     public static let minor: ChordDescriptor = [.m3, .M3]
 62 |     public static let diminished: ChordDescriptor = [.m3, .m3]
 63 |     public static let augmented: ChordDescriptor = [.M3, .M3]
    |                       |- warning: static property 'augmented' is not concurrency-safe because non-'Sendable' type 'ChordDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'augmented' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 64 | }
 65 |
/host/spi-builder-workspace/Sources/Pitch/Frequency.swift:25:15: error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
23 | ///     let mean: Frequency = 440.0 // => "a 440"
24 | ///
25 | public struct Frequency: NewType, SignedNumeric {
   |               `- error: type 'Frequency' does not conform to protocol 'AdditiveArithmetic'
26 |
27 |     // MARK: - Instance Properties
Swift.AdditiveArithmetic:4:17: note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
2 |     static var zero: Self { get }
3 |     static func + (lhs: Self, rhs: Self) -> Self
4 |     static func += (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '+=' with type '(inout Frequency, Frequency) -> ()'
5 |     static func - (lhs: Self, rhs: Self) -> Self
6 |     static func -= (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '-=' with type '(inout Frequency, Frequency) -> ()'
7 | }
Swift.AdditiveArithmetic:2:24: note: candidate exactly matches
1 | extension AdditiveArithmetic {
2 |     public static func += (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
3 |     public static func -= (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
4 | }
/host/spi-builder-workspace/.build/checkouts/Structure/Sources/DataStructures/Wrapping/NewType.swift:71:24: note: candidate exactly matches
69 |     }
70 |
71 |     public static func += (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
72 |         lhs = lhs + rhs
73 |     }
   :
77 |     }
78 |
79 |     public static func -= (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
80 |         lhs = lhs - rhs
81 |     }
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:111:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
109 |
110 |     /// Unison.
111 |     public static let unison = CompoundIntervalDescriptor(.unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
112 |
113 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:47:23: warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
 45 |
 46 |     /// The `unison` is the `zero` for the `CompoundIntervalDescriptor` `AdditiveGroup`.
 47 |     public static let zero: CompoundIntervalDescriptor = .unison
    |                       |- warning: static property 'zero' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'zero' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 48 |
 49 |     /// **Example Usage:**
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:178:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
176 |
177 |     /// Unison.
178 |     public static let unison = OrderedIntervalDescriptor(.perfect, .unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
179 |
180 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:114:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
112 |
113 |     /// Minor second.
114 |     public static let m2 = CompoundIntervalDescriptor(.m2)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
115 |
116 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:181:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
179 |
180 |     /// Minor second.
181 |     public static let m2 = OrderedIntervalDescriptor(.minor, .second)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
182 |
183 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:117:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
115 |
116 |     /// Major second.
117 |     public static let M2 = CompoundIntervalDescriptor(.M2)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
118 |
119 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:184:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
182 |
183 |     /// Major second.
184 |     public static let M2 = OrderedIntervalDescriptor(.major, .second)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
185 |
186 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:187:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
185 |
186 |     /// Minor third.
187 |     public static let m3 = OrderedIntervalDescriptor(.minor, .third)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
188 |
189 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:190:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
188 |
189 |     /// Major third.
190 |     public static let M3 = OrderedIntervalDescriptor(.major, .third)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
191 |
192 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:126:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
124 |
125 |     /// Diminished fourth.
126 |     public static let d4 = CompoundIntervalDescriptor(.d4)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
127 |
128 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:193:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
191 |
192 |     /// Diminished fourth.
193 |     public static let d4 = OrderedIntervalDescriptor(.diminished, .fourth)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
194 |
195 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:129:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
127 |
128 |     /// Perfect fourth.
129 |     public static let P4 = CompoundIntervalDescriptor(.P4)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
130 |
131 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:196:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
194 |
195 |     /// Perfect fourth.
196 |     public static let P4 = OrderedIntervalDescriptor(.perfect, .fourth)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
197 |
198 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:132:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
130 |
131 |     /// Augmented fourth.
132 |     public static let A4 = CompoundIntervalDescriptor(.A4)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
133 |
134 |     /// Diminished fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:202:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
200 |
201 |     /// Augmented fourth.
202 |     public static let A4 = OrderedIntervalDescriptor(.augmented, .fourth)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
203 |
204 |     /// Diminished fifth
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:135:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
133 |
134 |     /// Diminished fifth.
135 |     public static let d5 = CompoundIntervalDescriptor(.d5)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
136 |
137 |     /// Perfect fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:205:23: warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
203 |
204 |     /// Diminished fifth
205 |     public static let d5 = OrderedIntervalDescriptor(.diminished, .fifth)
    |                       |- warning: static property 'd5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
206 |
207 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:138:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
136 |
137 |     /// Perfect fifth.
138 |     public static let P5 = CompoundIntervalDescriptor(.P5)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
139 |
140 |     /// Augmented fifth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:199:23: warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
197 |
198 |     /// Perfect fifth.
199 |     public static let P5 = OrderedIntervalDescriptor(.perfect, .fifth)
    |                       |- warning: static property 'P5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
200 |
201 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:141:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
139 |
140 |     /// Augmented fifth.
141 |     public static let A5 = CompoundIntervalDescriptor(.A5)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
142 |
143 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:208:23: warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
206 |
207 |     /// Augmented fifth.
208 |     public static let A5 = OrderedIntervalDescriptor(.augmented, .fifth)
    |                       |- warning: static property 'A5' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A5' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
209 |
210 |     /// Minor sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:144:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
142 |
143 |     /// Minor sixth.
144 |     public static let m6 = CompoundIntervalDescriptor(.m6)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
145 |
146 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:211:23: warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
209 |
210 |     /// Minor sixth.
211 |     public static let m6 = OrderedIntervalDescriptor(.minor, .sixth)
    |                       |- warning: static property 'm6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
212 |
213 |     /// Major sixth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:147:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
145 |
146 |     /// Major sixth.
147 |     public static let M6 = CompoundIntervalDescriptor(.M6)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
148 |
149 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:214:23: warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
212 |
213 |     /// Major sixth.
214 |     public static let M6 = OrderedIntervalDescriptor(.major, .sixth)
    |                       |- warning: static property 'M6' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M6' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
215 |
216 |     /// Minor seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:150:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
148 |
149 |     /// Minor seventh.
150 |     public static let m7 = CompoundIntervalDescriptor(.m7)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
151 |
152 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:217:23: warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
215 |
216 |     /// Minor seventh.
217 |     public static let m7 = OrderedIntervalDescriptor(.minor, .seventh)
    |                       |- warning: static property 'm7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
218 |
219 |     /// Major seventh.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:153:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
151 |
152 |     /// Major seventh.
153 |     public static let M7 = CompoundIntervalDescriptor(.M7)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
154 |
155 |     /// Octave.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/OrderedIntervalDescriptor.swift:220:23: warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for ordered interval between two `Pitch` values.
 12 | public struct OrderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'OrderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
218 |
219 |     /// Major seventh.
220 |     public static let M7 = OrderedIntervalDescriptor(.major, .seventh)
    |                       |- warning: static property 'M7' is not concurrency-safe because non-'Sendable' type 'OrderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M7' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
221 |
222 |     // TODO: Add diminished / augmented imperfect intervals
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/CompoundIntervalDescriptor.swift:156:23: warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 11 | /// A descriptor for intervals between two `Pitch` values which takes into account octave
 12 | /// displacement.
 13 | public struct CompoundIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'CompoundIntervalDescriptor' conform to the 'Sendable' protocol
 14 |
 15 |     // MARK: - Instance Properties
    :
154 |
155 |     /// Octave.
156 |     public static let octave = CompoundIntervalDescriptor(.unison, displacedBy: 1)
    |                       |- warning: static property 'octave' is not concurrency-safe because non-'Sendable' type 'CompoundIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octave' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
157 |
158 |     // TODO: Add intervals spanning more than one octave
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:144:23: warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
142 |
143 |     /// Unison.
144 |     public static let unison = UnorderedIntervalDescriptor(.perfect, .unison)
    |                       |- warning: static property 'unison' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'unison' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
145 |
146 |     /// Minor second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:147:23: warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
145 |
146 |     /// Minor second.
147 |     public static let m2 = UnorderedIntervalDescriptor(.minor, .second)
    |                       |- warning: static property 'm2' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
148 |
149 |     /// Major second.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:150:23: warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
148 |
149 |     /// Major second.
150 |     public static let M2 = UnorderedIntervalDescriptor(.major, .second)
    |                       |- warning: static property 'M2' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M2' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
151 |
152 |     /// Minor third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:153:23: warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
151 |
152 |     /// Minor third.
153 |     public static let m3 = UnorderedIntervalDescriptor(.minor, .third)
    |                       |- warning: static property 'm3' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'm3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
154 |
155 |     /// Major third.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:156:23: warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
154 |
155 |     /// Major third.
156 |     public static let M3 = UnorderedIntervalDescriptor(.major, .third)
    |                       |- warning: static property 'M3' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'M3' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
157 |
158 |     /// Diminished fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:159:23: warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
157 |
158 |     /// Diminished fourth.
159 |     public static let d4 = UnorderedIntervalDescriptor(.diminished, .fourth)
    |                       |- warning: static property 'd4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'd4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
160 |
161 |     /// Perfect fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:162:23: warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
160 |
161 |     /// Perfect fourth.
162 |     public static let P4 = UnorderedIntervalDescriptor(.perfect, .fourth)
    |                       |- warning: static property 'P4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'P4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
163 |
164 |     /// Augmented fourth.
/host/spi-builder-workspace/Sources/Pitch/IntervalDescriptor/UnorderedIntervalDescriptor.swift:165:23: warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
 10 |
 11 | /// Descriptor for unordered intervals between two `Pitch.Class` values.
 12 | public struct UnorderedIntervalDescriptor: IntervalDescriptor {
    |               `- note: consider making struct 'UnorderedIntervalDescriptor' conform to the 'Sendable' protocol
 13 |
 14 |     // MARK: - Instance Properties
    :
163 |
164 |     /// Augmented fourth.
165 |     public static let A4 = UnorderedIntervalDescriptor(.augmented, .fourth)
    |                       |- warning: static property 'A4' is not concurrency-safe because non-'Sendable' type 'UnorderedIntervalDescriptor' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'A4' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
166 |
167 |     // TODO: Add diminished / augmented imperfect intervals
/host/spi-builder-workspace/Sources/Pitch/NoteNumber.swift:27:15: error: type 'NoteNumber' does not conform to protocol 'AdditiveArithmetic'
25 | ///     let cold: NoteNumber = 60
26 | ///
27 | public struct NoteNumber:
   |               `- error: type 'NoteNumber' does not conform to protocol 'AdditiveArithmetic'
28 |     NewType,
29 |     Comparable,
Swift.AdditiveArithmetic:4:17: note: multiple matching functions named '+=' with type '(inout NoteNumber, NoteNumber) -> ()'
2 |     static var zero: Self { get }
3 |     static func + (lhs: Self, rhs: Self) -> Self
4 |     static func += (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '+=' with type '(inout NoteNumber, NoteNumber) -> ()'
5 |     static func - (lhs: Self, rhs: Self) -> Self
6 |     static func -= (lhs: inout Self, rhs: Self)
  |                 `- note: multiple matching functions named '-=' with type '(inout NoteNumber, NoteNumber) -> ()'
7 | }
Swift.AdditiveArithmetic:2:24: note: candidate exactly matches
1 | extension AdditiveArithmetic {
2 |     public static func += (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
3 |     public static func -= (lhs: inout Self, rhs: Self)
  |                        `- note: candidate exactly matches
4 | }
/host/spi-builder-workspace/.build/checkouts/Structure/Sources/DataStructures/Wrapping/NewType.swift:71:24: note: candidate exactly matches
69 |     }
70 |
71 |     public static func += (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
72 |         lhs = lhs + rhs
73 |     }
   :
77 |     }
78 |
79 |     public static func -= (lhs: inout Self, rhs: Self) {
   |                        `- note: candidate exactly matches
80 |         lhs = lhs - rhs
81 |     }
/host/spi-builder-workspace/Sources/Pitch/Pitch.swift:69:59: warning: initializer 'init(integerLiteral:)' cannot be used in a default argument value because 'DataStructures' was not imported by this file; this is an error in the Swift 6 language mode
67 |     /// The `Frequency` representation of this `Pitch`, with the given tuning `referenceFrequency`
68 |     /// at the given `referenceNoteNumber`.
69 |     public func frequency(referenceFrequency: Frequency = 440, referenceNoteNumber: NoteNumber = 69)
   |                                                           |- warning: initializer 'init(integerLiteral:)' cannot be used in a default argument value because 'DataStructures' was not imported by this file; this is an error in the Swift 6 language mode
   |                                                           `- note: The missing import of module 'DataStructures' will be added implicitly
70 |         -> Frequency
71 |     {
/host/spi-builder-workspace/Sources/Pitch/Pitch.swift:69:98: warning: initializer 'init(integerLiteral:)' cannot be used in a default argument value because 'DataStructures' was not imported by this file; this is an error in the Swift 6 language mode
67 |     /// The `Frequency` representation of this `Pitch`, with the given tuning `referenceFrequency`
68 |     /// at the given `referenceNoteNumber`.
69 |     public func frequency(referenceFrequency: Frequency = 440, referenceNoteNumber: NoteNumber = 69)
   |                                                                                                  |- warning: initializer 'init(integerLiteral:)' cannot be used in a default argument value because 'DataStructures' was not imported by this file; this is an error in the Swift 6 language mode
   |                                                                                                  `- note: The missing import of module 'DataStructures' will be added implicitly
70 |         -> Frequency
71 |     {
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:69:23: warning: static property 'chromatic' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 67 |
 68 |     /// Chromatic scale interval pattern.
 69 |     public static let chromatic: Scale.IntervalPattern = [1,1,1,1,1,1,1,1,1,1,1,1]
    |                       |- warning: static property 'chromatic' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'chromatic' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 70 |
 71 |     /// Major scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:72:23: warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 70 |
 71 |     /// Major scale interval pattern.
 72 |     public static let major: Scale.IntervalPattern = [2,2,1,2,2,2,1]
    |                       |- warning: static property 'major' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'major' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 73 |
 74 |     /// Chromatic scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:75:23: warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 73 |
 74 |     /// Chromatic scale interval pattern.
 75 |     public static let minor: Scale.IntervalPattern = [2,1,2,2,1,2,2]
    |                       |- warning: static property 'minor' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'minor' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 76 |
 77 |     /// Melodic minor ascending scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:78:23: warning: static property 'melodicMinorAscending' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 76 |
 77 |     /// Melodic minor ascending scale interval pattern.
 78 |     public static let melodicMinorAscending: Scale.IntervalPattern = [2,1,2,2,2,2,1]
    |                       |- warning: static property 'melodicMinorAscending' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'melodicMinorAscending' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 79 |
 80 |     /// Melodic minor descending scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:81:23: warning: static property 'melodicMinorDescending' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 79 |
 80 |     /// Melodic minor descending scale interval pattern.
 81 |     public static let melodicMinorDescending: Scale.IntervalPattern = .minor
    |                       |- warning: static property 'melodicMinorDescending' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'melodicMinorDescending' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 82 |
 83 |     /// Harmonic minor scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:84:23: warning: static property 'harmonicMinor' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 82 |
 83 |     /// Harmonic minor scale interval pattern.
 84 |     public static let harmonicMinor: Scale.IntervalPattern = [2,1,2,2,1,3,1]
    |                       |- warning: static property 'harmonicMinor' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'harmonicMinor' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 85 |
 86 |     /// Octatonic 2-1 scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:87:23: warning: static property 'octatonic21' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 85 |
 86 |     /// Octatonic 2-1 scale interval pattern.
 87 |     public static let octatonic21: Scale.IntervalPattern = [2,1,2,1,2,1,2,1]
    |                       |- warning: static property 'octatonic21' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octatonic21' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 88 |
 89 |     /// Octatonic 1-2 scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:90:23: warning: static property 'octatonic12' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 88 |
 89 |     /// Octatonic 1-2 scale interval pattern.
 90 |     public static let octatonic12: Scale.IntervalPattern = [1,2,1,2,1,2,1,2]
    |                       |- warning: static property 'octatonic12' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'octatonic12' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 91 |
 92 |     /// Whole tone scale interval pattern.
/host/spi-builder-workspace/Sources/Pitch/Scale/Scale.IntervalPattern.swift:93:23: warning: static property 'wholeTone' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
 21 |     ///     let tetrachord = IntervalPattern([2,2,1], isLooping: false)
 22 |     ///
 23 |     public struct IntervalPattern {
    |                   `- note: consider making struct 'IntervalPattern' conform to the 'Sendable' protocol
 24 |
 25 |         // MARK: - Instance Properties
    :
 91 |
 92 |     /// Whole tone scale interval pattern.
 93 |     public static let wholeTone: Scale.IntervalPattern = [2,2,2,2,2,2]
    |                       |- warning: static property 'wholeTone' is not concurrency-safe because non-'Sendable' type 'Scale.IntervalPattern' may have shared mutable state; this is an error in the Swift 6 language mode
    |                       |- note: annotate 'wholeTone' with '@MainActor' if property should only be accessed from the main actor
    |                       `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
 94 | }
 95 |
[162/172] Compiling Duration Tempo.swift
/host/spi-builder-workspace/Sources/Duration/Rhythm/ProportionTree.swift:34:55: warning: property 'sum' cannot be used in an '@inlinable' function because 'Algebra' was not imported by this file; this is an error in the Swift 6 language mode
 32 |                 return .leaf(accum)
 33 |             case .branch(let duration, let trees):
 34 |                 let sum = trees.lazy.map { $0.value }.sum
    |                                                       |- warning: property 'sum' cannot be used in an '@inlinable' function because 'Algebra' was not imported by this file; this is an error in the Swift 6 language mode
    |                                                       `- note: The missing import of module 'Algebra' will be added implicitly
 35 |                 let scale = Fraction(duration, sum)
 36 |                 return .branch(accum, trees.map { traverse($0, accum: accum * scale) })
BUILD FAILURE 6.0 linux