Swift Package IndexBuild Information
Successful build of Embassy, reference 4.1.6 (8469f2), with Swift 6.1 for macOS (SPM) on 27 Apr 2026 12:47:48 UTC.
Swift 6 data race errors: 2
Build Command
env DEVELOPER_DIR=/Applications/Xcode-16.3.0.app xcrun swift build --arch arm64 -Xswiftc -Xfrontend -Xswiftc -stats-output-dir -Xswiftc -Xfrontend -Xswiftc .stats -Xswiftc -strict-concurrency=complete -Xswiftc -enable-upcoming-feature -Xswiftc StrictConcurrency -Xswiftc -enable-upcoming-feature -Xswiftc DisableOutwardActorInference -Xswiftc -enable-upcoming-feature -Xswiftc GlobalActorIsolatedTypesUsability -Xswiftc -enable-upcoming-feature -Xswiftc InferSendableFromCapturesBuild Log
========================================
RunAll
========================================
Builder version: 4.70.0
Interrupt handler set up.
========================================
Checkout
========================================
Clone URL: https://github.com/envoy/Embassy.git
Reference: 4.1.6
Initialized empty Git repository in /Users/admin/builder/spi-builder-workspace/.git/
From https://github.com/envoy/Embassy
* tag 4.1.6 -> FETCH_HEAD
HEAD is now at 8469f2c Merge pull request #106 from mahyarwd/fix-4.1.5-build-error
Cloned https://github.com/envoy/Embassy.git
Revision (git rev-parse @):
8469f2c1b334a7c1c3566e2cb2f97826c7cca898
SUCCESS checkout https://github.com/envoy/Embassy.git at 4.1.6
========================================
Build
========================================
Selected platform: macosSpm
Swift version: 6.1
Building package at path: $PWD
https://github.com/envoy/Embassy.git
https://github.com/envoy/Embassy.git
{
"dependencies" : [
],
"manifest_display_name" : "Embassy",
"name" : "Embassy",
"path" : "/Users/admin/builder/spi-builder-workspace",
"platforms" : [
],
"products" : [
{
"name" : "Embassy",
"targets" : [
"Embassy"
],
"type" : {
"library" : [
"automatic"
]
}
}
],
"targets" : [
{
"c99name" : "Embassy",
"module_type" : "SwiftTarget",
"name" : "Embassy",
"path" : "Sources",
"product_memberships" : [
"Embassy"
],
"sources" : [
"Atomic.swift",
"DefaultHTTPServer.swift",
"DefaultLogFormatter.swift",
"DefaultLogger.swift",
"Errors.swift",
"EventLoop.swift",
"FileLogHandler.swift",
"HTTPConnection.swift",
"HTTPHeaderParser.swift",
"HTTPRequest.swift",
"HTTPServer.swift",
"HeapSort.swift",
"IOUtils.swift",
"KqueueSelector.swift",
"LogFormatter.swift",
"LogHandler.swift",
"Logger.swift",
"MultiDictionary.swift",
"PrintLogHandler.swift",
"PropagateLogHandler.swift",
"SWSGI.swift",
"SWSGIUtils.swift",
"SelectSelector.swift",
"Selector.swift",
"SelectorEventLoop.swift",
"SystemLibrary.swift",
"TCPSocket.swift",
"TransformLogHandler.swift",
"Transport.swift"
],
"type" : "library"
}
],
"tools_version" : "4.2"
}
Running build ...
env DEVELOPER_DIR=/Applications/Xcode-16.3.0.app xcrun swift build --arch arm64 -Xswiftc -Xfrontend -Xswiftc -stats-output-dir -Xswiftc -Xfrontend -Xswiftc .stats -Xswiftc -strict-concurrency=complete -Xswiftc -enable-upcoming-feature -Xswiftc StrictConcurrency -Xswiftc -enable-upcoming-feature -Xswiftc DisableOutwardActorInference -Xswiftc -enable-upcoming-feature -Xswiftc GlobalActorIsolatedTypesUsability -Xswiftc -enable-upcoming-feature -Xswiftc InferSendableFromCaptures
Building for debugging...
[0/2] Write sources
[1/2] Write swift-version-2F0A5646E1D333AE.txt
[3/30] Emitting module Embassy
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:100:20: warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
98 | static let select = Darwin.select
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'htons' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
102 | static let connect = Darwin.connect
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:101:20: warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'ntohs' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
102 | static let connect = Darwin.connect
103 | static let bind = Darwin.bind
[4/32] Compiling Embassy SelectorEventLoop.swift
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:100:20: warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
98 | static let select = Darwin.select
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'htons' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
102 | static let connect = Darwin.connect
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:101:20: warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'ntohs' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
102 | static let connect = Darwin.connect
103 | static let bind = Darwin.bind
/Users/admin/builder/spi-builder-workspace/Sources/TCPSocket.swift:291:17: warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
289 | inet_ntop(
290 | family,
291 | &addrStruct,
| `- warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
292 | pointer,
293 | socklen_t(addressLength)
[5/32] Compiling Embassy SystemLibrary.swift
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:100:20: warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
98 | static let select = Darwin.select
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'htons' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
102 | static let connect = Darwin.connect
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:101:20: warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'ntohs' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
102 | static let connect = Darwin.connect
103 | static let bind = Darwin.bind
/Users/admin/builder/spi-builder-workspace/Sources/TCPSocket.swift:291:17: warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
289 | inet_ntop(
290 | family,
291 | &addrStruct,
| `- warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
292 | pointer,
293 | socklen_t(addressLength)
[6/32] Compiling Embassy TCPSocket.swift
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:100:20: warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
98 | static let select = Darwin.select
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'htons' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'htons' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
102 | static let connect = Darwin.connect
<unknown>:0: note: a function type must be marked '@Sendable' to conform to 'Sendable'
/Users/admin/builder/spi-builder-workspace/Sources/SystemLibrary.swift:101:20: warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
99 | static let isLittleEndian = Int(OSHostByteOrder()) == OSLittleEndian
100 | static let htons = isLittleEndian ? _OSSwapInt16 : { $0 }
101 | static let ntohs = isLittleEndian ? _OSSwapInt16 : { $0 }
| |- warning: static property 'ntohs' is not concurrency-safe because non-'Sendable' type '(__uint16_t) -> __uint16_t' (aka '(UInt16) -> UInt16') may have shared mutable state; this is an error in the Swift 6 language mode
| |- note: add '@MainActor' to make static property 'ntohs' part of global actor 'MainActor'
| `- note: disable concurrency-safety checks if accesses are protected by an external synchronization mechanism
102 | static let connect = Darwin.connect
103 | static let bind = Darwin.bind
/Users/admin/builder/spi-builder-workspace/Sources/TCPSocket.swift:291:17: warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
289 | inet_ntop(
290 | family,
291 | &addrStruct,
| `- warning: forming 'UnsafeRawPointer' to a variable of type 'StructType'; this is likely incorrect because 'StructType' may contain an object reference.
292 | pointer,
293 | socklen_t(addressLength)
[7/32] Compiling Embassy TransformLogHandler.swift
[8/32] Compiling Embassy Transport.swift
[9/32] Compiling Embassy HTTPRequest.swift
[10/32] Compiling Embassy HTTPServer.swift
[11/32] Compiling Embassy HeapSort.swift
[12/32] Compiling Embassy DefaultLogger.swift
[13/32] Compiling Embassy Errors.swift
[14/32] Compiling Embassy EventLoop.swift
[15/32] Compiling Embassy SWSGIUtils.swift
[16/32] Compiling Embassy SelectSelector.swift
[17/32] Compiling Embassy Selector.swift
[18/32] Compiling Embassy Atomic.swift
[19/32] Compiling Embassy DefaultHTTPServer.swift
[20/32] Compiling Embassy DefaultLogFormatter.swift
[21/32] Compiling Embassy FileLogHandler.swift
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:29:32: warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
11 |
12 | /// A log handler which writes log records to given file handle
13 | public struct FileLogHandler: LogHandler {
| `- note: consider making struct 'FileLogHandler' conform to the 'Sendable' protocol
14 | let fileHandle: FileHandle
15 | public var formatter: LogFormatter?
:
27 | public func emit(record: LogRecord) {
28 | queue.async {
29 | if let formatter = self.formatter {
| `- warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
30 | let msg = formatter.format(record: record) + "\n"
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:30:52: warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
28 | queue.async {
29 | if let formatter = self.formatter {
30 | let msg = formatter.format(record: record) + "\n"
| `- warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
32 | self.fileHandle.synchronizeFile()
/Users/admin/builder/spi-builder-workspace/Sources/Logger.swift:37:15: note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
35 | }
36 |
37 | public struct LogRecord {
| `- note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
38 | let loggerName: String
39 | let level: LogLevel
[22/32] Compiling Embassy HTTPConnection.swift
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:29:32: warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
11 |
12 | /// A log handler which writes log records to given file handle
13 | public struct FileLogHandler: LogHandler {
| `- note: consider making struct 'FileLogHandler' conform to the 'Sendable' protocol
14 | let fileHandle: FileHandle
15 | public var formatter: LogFormatter?
:
27 | public func emit(record: LogRecord) {
28 | queue.async {
29 | if let formatter = self.formatter {
| `- warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
30 | let msg = formatter.format(record: record) + "\n"
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:30:52: warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
28 | queue.async {
29 | if let formatter = self.formatter {
30 | let msg = formatter.format(record: record) + "\n"
| `- warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
32 | self.fileHandle.synchronizeFile()
/Users/admin/builder/spi-builder-workspace/Sources/Logger.swift:37:15: note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
35 | }
36 |
37 | public struct LogRecord {
| `- note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
38 | let loggerName: String
39 | let level: LogLevel
[23/32] Compiling Embassy HTTPHeaderParser.swift
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:29:32: warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
11 |
12 | /// A log handler which writes log records to given file handle
13 | public struct FileLogHandler: LogHandler {
| `- note: consider making struct 'FileLogHandler' conform to the 'Sendable' protocol
14 | let fileHandle: FileHandle
15 | public var formatter: LogFormatter?
:
27 | public func emit(record: LogRecord) {
28 | queue.async {
29 | if let formatter = self.formatter {
| `- warning: capture of 'self' with non-sendable type 'FileLogHandler' in a '@Sendable' closure
30 | let msg = formatter.format(record: record) + "\n"
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
/Users/admin/builder/spi-builder-workspace/Sources/FileLogHandler.swift:30:52: warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
28 | queue.async {
29 | if let formatter = self.formatter {
30 | let msg = formatter.format(record: record) + "\n"
| `- warning: capture of 'record' with non-sendable type 'LogRecord' in a '@Sendable' closure
31 | self.fileHandle.write(msg.data(using: String.Encoding.utf8)!)
32 | self.fileHandle.synchronizeFile()
/Users/admin/builder/spi-builder-workspace/Sources/Logger.swift:37:15: note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
35 | }
36 |
37 | public struct LogRecord {
| `- note: consider making struct 'LogRecord' conform to the 'Sendable' protocol
38 | let loggerName: String
39 | let level: LogLevel
[24/32] Compiling Embassy PrintLogHandler.swift
[25/32] Compiling Embassy PropagateLogHandler.swift
[26/32] Compiling Embassy SWSGI.swift
[27/32] Compiling Embassy IOUtils.swift
[28/32] Compiling Embassy KqueueSelector.swift
[29/32] Compiling Embassy LogFormatter.swift
[30/32] Compiling Embassy LogHandler.swift
[31/32] Compiling Embassy Logger.swift
[32/32] Compiling Embassy MultiDictionary.swift
Build complete! (5.44s)
Build complete.
{
"dependencies" : [
],
"manifest_display_name" : "Embassy",
"name" : "Embassy",
"path" : "/Users/admin/builder/spi-builder-workspace",
"platforms" : [
],
"products" : [
{
"name" : "Embassy",
"targets" : [
"Embassy"
],
"type" : {
"library" : [
"automatic"
]
}
}
],
"targets" : [
{
"c99name" : "Embassy",
"module_type" : "SwiftTarget",
"name" : "Embassy",
"path" : "Sources",
"product_memberships" : [
"Embassy"
],
"sources" : [
"Atomic.swift",
"DefaultHTTPServer.swift",
"DefaultLogFormatter.swift",
"DefaultLogger.swift",
"Errors.swift",
"EventLoop.swift",
"FileLogHandler.swift",
"HTTPConnection.swift",
"HTTPHeaderParser.swift",
"HTTPRequest.swift",
"HTTPServer.swift",
"HeapSort.swift",
"IOUtils.swift",
"KqueueSelector.swift",
"LogFormatter.swift",
"LogHandler.swift",
"Logger.swift",
"MultiDictionary.swift",
"PrintLogHandler.swift",
"PropagateLogHandler.swift",
"SWSGI.swift",
"SWSGIUtils.swift",
"SelectSelector.swift",
"Selector.swift",
"SelectorEventLoop.swift",
"SystemLibrary.swift",
"TCPSocket.swift",
"TransformLogHandler.swift",
"Transport.swift"
],
"type" : "library"
}
],
"tools_version" : "4.2"
}
Done.