6.0.3 toolchain on macOS crashes when compiling Swift Lambda Runtime library in Swift 6 mode

[sebsto]

Description

The compiler crashes with a stack trace when compiling the Swift AWS Lambda Runtime library on macOS and Linux in Swift 6 mode.

It fails with pass #1183 SILFunctionTransform "TransferNonSendable" on SILFunction on one of the two defer() (here and here) calls made in [LambdaRuntimeClient.swift](https://github.com/swift-server/swift-aws-lambda-runtime/blob/main/Sources/AWSLambdaRuntimeCore/LambdaRuntimeClient.swift)

The full error is shared below in the stack dum section.

Reproduction

git clone https://github.com/swift-server/swift-aws-lambda-runtime

Edit Package.swift and remove line 40

Then compile

swift build

Stack dump

Stack dump:
0.      Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/ControlPlaneRequest.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/ControlPlaneRequestEncoder.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/Lambda+Codable.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/Lambda+LocalServer.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/Lambda.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaContext.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaHandlers.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaRequestID.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaRuntime.swift -primary-file /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaRuntimeClient.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaRuntimeClientProtocol.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/LambdaRuntimeError.swift /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/Sources/AWSLambdaRuntimeCore/Utils.swift -emit-dependencies-path /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/AWSLambdaRuntimeCore.build/LambdaRuntimeClient.d -emit-reference-dependencies-path /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/AWSLambdaRuntimeCore.build/LambdaRuntimeClient.swiftdeps -target arm64-apple-macosx15.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -stack-check -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.2.sdk -I /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/Modules -I /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/lib -F /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -color-diagnostics -enable-testing -g -debug-info-format=dwarf -dwarf-version=5 -module-cache-path /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/ModuleCache -swift-version 6 -Onone -D SWIFT_PACKAGE -D DEBUG -new-driver-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-driver -empty-abi-descriptor -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -enable-anonymous-context-mangled-names -file-compilation-dir /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/CNIOLLHTTP.build/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOLLHTTP/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-atomics/Sources/_AtomicsShims/include/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-atomics/Sources/_AtomicsShims/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/CNIOWASI.build/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOWASI/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOWindows/include/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOWindows/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/CNIOLinux.build/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOLinux/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/CNIODarwin.build/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIODarwin/include -Xcc -fmodule-map-file=/Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/CNIOAtomics.build/module.modulemap -Xcc -I -Xcc /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/checkouts/swift-nio/Sources/CNIOAtomics/include -Xcc -isysroot -Xcc /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.2.sdk -Xcc -F -Xcc /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -Xcc -fPIC -Xcc -g -module-name AWSLambdaRuntimeCore -package-name swift_aws_lambda_runtime -disable-clang-spi -target-sdk-version 15.2 -target-sdk-name macosx15.2 -external-plugin-path /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/lib/swift/host/plugins#/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -external-plugin-path /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/local/lib/swift/host/plugins#/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -plugin-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/local/lib/swift/host/plugins -parse-as-library -o /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/AWSLambdaRuntimeCore.build/LambdaRuntimeClient.swift.o -index-store-path /Users/sst/Documents/code/swift/lambda/swift-aws-lambda-runtime/.build/arm64-apple-macosx/debug/index/store -index-system-modules
1.      Apple Swift version 6.0.3 (swiftlang-6.0.3.1.10 clang-1600.0.30.1)
2.      Compiling with the current language version
3.      While evaluating request ExecuteSILPipelineRequest(Run pipelines { Mandatory Diagnostic Passes + Enabling Optimization Passes } on SIL for AWSLambdaRuntimeCore)
4.      While running pass #1183 SILFunctionTransform "TransferNonSendable" on SILFunction "@$s20AWSLambdaRuntimeCore06LambdaB6ClientC19makeOrGetConnection33_59FD0B78DD5D4250AAE9FA289B9DF5CFLLAA0D14ChannelHandlerAELLCyACGyYaKF6$deferL_yyF".
 for '$defer()' (in module 'AWSLambdaRuntimeCore')
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010a44ea9c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x000000010a44ccf0 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x000000010a44f068 SignalHandler(int) + 292
3  libsystem_platform.dylib 0x000000018d066e04 _sigtramp + 56
4  swift-frontend           0x000000010682f374 swift::ActorIsolation::printForDiagnostics(llvm::raw_ostream&, llvm::StringRef) const + 360
5  swift-frontend           0x000000010682f374 swift::ActorIsolation::printForDiagnostics(llvm::raw_ostream&, llvm::StringRef) const + 360
6  swift-frontend           0x0000000105e64d8c swift::SILIsolationInfo::printForDiagnostics(llvm::raw_ostream&) const + 448
7  swift-frontend           0x0000000105c07c7c (anonymous namespace)::TransferNonSendableImpl::emitDiagnostics() + 14148
8  swift-frontend           0x0000000105c04348 (anonymous namespace)::TransferNonSendable::run() + 460
9  swift-frontend           0x0000000105c39b74 swift::SILPassManager::runFunctionPasses(unsigned int, unsigned int) + 3448
10 swift-frontend           0x0000000105c36158 swift::SILPassManager::executePassPipelinePlan(swift::SILPassPipelinePlan const&) + 11968
11 swift-frontend           0x0000000105c6f6a4 swift::SimpleRequest<swift::ExecuteSILPipelineRequest, std::__1::tuple<> (swift::SILPipelineExecutionDescriptor), (swift::RequestFlags)1>::evaluateRequest(swift::ExecuteSILPipelineRequest const&, swift::Evaluator&) + 56
12 swift-frontend           0x0000000105c53008 swift::ExecuteSILPipelineRequest::OutputType swift::Evaluator::getResultUncached<swift::ExecuteSILPipelineRequest, swift::ExecuteSILPipelineRequest::OutputType swift::evaluateOrFatal<swift::ExecuteSILPipelineRequest>(swift::Evaluator&, swift::ExecuteSILPipelineRequest)::'lambda'()>(swift::ExecuteSILPipelineRequest const&, swift::ExecuteSILPipelineRequest::OutputType swift::evaluateOrFatal<swift::ExecuteSILPipelineRequest>(swift::Evaluator&, swift::ExecuteSILPipelineRequest)::'lambda'()) + 412
13 swift-frontend           0x0000000105c55784 swift::runSILDiagnosticPasses(swift::SILModule&) + 612
14 swift-frontend           0x00000001051cc0e4 swift::CompilerInstance::performSILProcessing(swift::SILModule*) + 84
15 swift-frontend           0x0000000104df69c4 performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 1376
16 swift-frontend           0x0000000104df5bd0 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 984
17 swift-frontend           0x0000000104df8e88 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1684
18 swift-frontend           0x0000000104df7bb4 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3572
19 swift-frontend           0x0000000104d7ea5c swift::mainEntry(int, char const**) + 3680
20 dyld                     0x000000018ccb0274 start + 2840
[259/270] Linking MockServer                   0x000000018ccb0274 start + 2840

Expected behavior

Should compile.

Environment

$ swiftc --version
Swift version 6.0.3 (swift-6.0.3-RELEASE)
Target: x86_64-unknown-linux-gnu

$ swiftc --version
swift-driver version: 1.115.1 Apple Swift version 6.0.3 (swiftlang-6.0.3.1.10 clang-1600.0.30.1)
Target: arm64-apple-macosx15.0

Additional information

No response