[6.2 nightly] Compilation crash: "Found outside of lifetime use?!" "Found ownership error?!"

[MahdiBM]

Description

See repro / stack-dump.

Reproduction

docker run --rm -it swiftlang/swift:nightly-6.2-noble bash -c '
  git clone https://github.com/vapor/penny-bot
  cd penny-bot
  git checkout 8546ff9148735431978eccb37e24488af79a7eb2
  swift build --build-tests -c release
'

Stack dump

[1048/1071] Compiling DiscordLogger +DiscordGlobalConfiguration.swift
error: compile command failed due to signal 6 (use -v to see invocation)
Begin Error in Function: '$s14DiscordGateway0A5CacheC11handleEvent33_6775718AF35C566C334CDE3CB8BA8CFCLLyy0A6Models0B0V0E0VF'
Found outside of lifetime use?!
Value:   %5848 = begin_borrow %5845 : $Gateway.MessageDeleteBulk // users: %9527, %5869, %5878, %5849
Consuming User:   end_borrow %5848 : $Gateway.MessageDeleteBulk   // id: %9527
Non Consuming User:   end_borrow %5855 : $Builtin.SILToken            // id: %9530
Block: bb882

End Error in Function: '$s14DiscordGateway0A5CacheC11handleEvent33_6775718AF35C566C334CDE3CB8BA8CFCLLyy0A6Models0B0V0E0VF'
Found ownership error?!
<unknown>:0: error: fatal error encountered during compilation; please submit a bug report (https://swift.org/contributing/#reporting-bugs)
<unknown>:0: note: triggering standard assertion failure routine
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.	Program arguments: /usr/bin/swift-frontend -frontend -c /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/Backoff.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/BotGatewayManager.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/DiscordAsyncStream.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/DiscordCache.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/GatewayEventHandler.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/GatewayManager.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/SerialQueue.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/ShardCoordinator.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/ShardingGatewayManager.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/ZlibDecompressorWSExtension.swift /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/exports.swift -supplementary-output-file-map /tmp/TemporaryDirectory.WohzVB/supplementaryOutputs-1 -target x86_64-unknown-linux-gnu -disable-objc-interop -I /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/Modules -no-color-diagnostics -Xcc -fno-color-diagnostics -enable-testing -g -debug-info-format=dwarf -dwarf-version=4 -module-cache-path /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/ModuleCache -suppress-warnings -swift-version 6 -O -D SWIFT_PACKAGE -D SWIFT_MODULE_RESOURCE_BUNDLE_UNAVAILABLE -load-plugin-executable /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/UnstableEnumMacro-tool#UnstableEnumMacro -enable-upcoming-feature ExistentialAny -empty-abi-descriptor -file-compilation-dir /__w/penny-bot/penny-bot -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOLLHTTP.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOLLHTTP/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOAtomics.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOAtomics/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/checkouts/swift-atomics/Sources/_AtomicsShims/include/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-atomics/Sources/_AtomicsShims/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOWASI.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOWASI/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOWindows/include/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOWindows/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOLinux.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOLinux/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIODarwin.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIODarwin/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOPosix.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOPosix/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/checkouts/swift-numerics/Sources/_NumericsShims/include/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-numerics/Sources/_NumericsShims/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOExtrasZlib.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio-extras/Sources/CNIOExtrasZlib/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOBoringSSLShims.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio-ssl/Sources/CNIOBoringSSLShims/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/checkouts/swift-nio-ssl/Sources/CNIOBoringSSL/include/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio-ssl/Sources/CNIOBoringSSL/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CAsyncHTTPClient.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/async-http-client/Sources/CAsyncHTTPClient/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CNIOSHA1.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/swift-nio/Sources/CNIOSHA1/include -Xcc -fmodule-map-file=/__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/CCompressZlib.build/module.modulemap -Xcc -I -Xcc /__w/penny-bot/penny-bot/.build/checkouts/compress-nio/Sources/CCompressZlib/include -Xcc -fPIC -Xcc -g -Xcc -fno-omit-frame-pointer -no-auto-bridging-header-chaining -module-name DiscordGateway -package-name discordbm -in-process-plugin-server-path /usr/lib/swift/host/libSwiftInProcPluginServer.so -plugin-path /usr/lib/swift/host/plugins -plugin-path /usr/local/lib/swift/host/plugins -enable-default-cmo -parse-as-library -num-threads 4 -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/Backoff.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/BotGatewayManager.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/DiscordAsyncStream.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/DiscordCache.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/GatewayEventHandler.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/GatewayManager.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/SerialQueue.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/ShardCoordinator.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/ShardingGatewayManager.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/ZlibDecompressorWSExtension.swift.o -o /__w/penny-bot/penny-bot/.build/x86_64-unknown-linux-gnu/release/DiscordGateway.build/exports.swift.o
1.	Swift version 6.2-dev (LLVM a96b21200f3b578, Swift 73209e1ea0a4f97)
2.	Compiling with the current language version
3.	While evaluating request ExecuteSILPipelineRequest(Run pipelines { PrepareOptimizationPasses, EarlyModulePasses, HighLevel,Function+EarlyLoopOpt, HighLevel,Module+StackPromote, MidLevel,Function, ClosureSpecialize, LowLevel,Function, LateLoopOpt, SIL Debug Info Generator } on SIL for DiscordGateway)
4.	While running pass #283014 SILFunctionTransform "CopyPropagation" on SILFunction "@$s14DiscordGateway0A5CacheC11handleEvent33_6775718AF35C566C334CDE3CB8BA8CFCLLyy0A6Models0B0V0E0VF".
 for 'handleEvent(_:)' (at /__w/penny-bot/penny-bot/.build/checkouts/DiscordBM/Sources/DiscordGateway/DiscordCache.swift:393:13)
 #0 0x000055f38dac6678 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/bin/swift-frontend+0x8c24678)
 #1 0x000055f38dac421e llvm::sys::RunSignalHandlers() (/usr/bin/swift-frontend+0x8c2221e)
 #2 0x000055f38dac6d11 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007ff1a769a330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
 #4 0x00007ff1a76f3b2c pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x9eb2c)
 #5 0x00007ff1a769a27e raise (/lib/x86_64-linux-gnu/libc.so.6+0x4527e)
 #6 0x00007ff1a767d8ff abort (/lib/x86_64-linux-gnu/libc.so.6+0x288ff)
 #7 0x000055f38613d755 swift::DiagnosticHelper::Implementation::diagnoseFatalError(char const*, bool) crtstuff.c:0:0
 #8 0x000055f38da18849 llvm::report_fatal_error(llvm::Twine const&, bool) (/usr/bin/swift-frontend+0x8b76849)
 #9 0x000055f38da18736 (/usr/bin/swift-frontend+0x8b76736)
#10 0x000055f3871ee584 swift::LinearLifetimeChecker::ErrorBuilder::handleError(llvm::function_ref<void ()>&&, bool) const crtstuff.c:0:0
#11 0x000055f3871ead0d swift::LinearLifetimeChecker::checkValueImpl(swift::SILValue, llvm::ArrayRef<swift::Operand*>, llvm::ArrayRef<swift::Operand*>, swift::LinearLifetimeChecker::ErrorBuilder&, std::optional<llvm::function_ref<void (swift::SILBasicBlock*)>>, std::optional<llvm::function_ref<void (swift::Operand*)>>) (/usr/bin/swift-frontend+0x2348d0d)
#12 0x000055f3871ec46d swift::LinearLifetimeChecker::checkValue(swift::SILValue, llvm::ArrayRef<swift::Operand*>, llvm::ArrayRef<swift::Operand*>, swift::LinearLifetimeChecker::ErrorBuilder&) (/usr/bin/swift-frontend+0x234a46d)
#13 0x000055f3871f0b3b swift::SILValueOwnershipChecker::check() (/usr/bin/swift-frontend+0x234eb3b)
#14 0x000055f3871f35d4 verifySILValueHelper(swift::SILFunction const*, swift::SILValue, swift::LinearLifetimeChecker::ErrorBuilder&, swift::DeadEndBlocks*, swift::GuaranteedPhiVerifier&) SILOwnershipVerifier.cpp:0:0
#15 0x000055f3871f3ac2 swift::SILFunction::verifyOwnership(swift::DeadEndBlocks*) const (/usr/bin/swift-frontend+0x2351ac2)
#16 0x000055f38688cc7c (anonymous namespace)::CopyPropagation::run() CopyPropagation.cpp:0:0
#17 0x000055f3867d1ce0 swift::SILPassManager::runPassOnFunction(unsigned int, swift::SILFunction*) (/usr/bin/swift-frontend+0x192fce0)
#18 0x000055f3867d2ef1 swift::SILPassManager::runFunctionPasses(unsigned int, unsigned int) (/usr/bin/swift-frontend+0x1930ef1)
#19 0x000055f3867cf928 swift::SILPassManager::executePassPipelinePlan(swift::SILPassPipelinePlan const&) (/usr/bin/swift-frontend+0x192d928)
#20 0x000055f3867cf8dd swift::ExecuteSILPipelineRequest::evaluate(swift::Evaluator&, swift::SILPipelineExecutionDescriptor) const (/usr/bin/swift-frontend+0x192d8dd)
#21 0x000055f3867f25fa swift::SimpleRequest<swift::ExecuteSILPipelineRequest, std::tuple<> (swift::SILPipelineExecutionDescriptor), (swift::RequestFlags)1>::evaluateRequest(swift::ExecuteSILPipelineRequest const&, swift::Evaluator&) crtstuff.c:0:0
#22 0x000055f3867ddbb6 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'()) crtstuff.c:0:0
#23 0x000055f3867cfb1f swift::executePassPipelinePlan(swift::SILModule*, swift::SILPassPipelinePlan const&, bool, swift::irgen::IRGenModule*) (/usr/bin/swift-frontend+0x192db1f)
#24 0x000055f3867df60b swift::runSILOptimizationPasses(swift::SILModule&) (/usr/bin/swift-frontend+0x193d60b)
#25 0x000055f38614c03e swift::CompilerInstance::performSILProcessing(swift::SILModule*) (/usr/bin/swift-frontend+0x12aa03e)
#26 0x000055f385de28f7 performCompileStepsPostSILGen(swift::CompilerInstance&, std::unique_ptr<swift::SILModule, std::default_delete<swift::SILModule>>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) FrontendTool.cpp:0:0
#27 0x000055f385de1c62 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) (/usr/bin/swift-frontend+0xf3fc62)
#28 0x000055f385df354a withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) FrontendTool.cpp:0:0
#29 0x000055f385de471e performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) FrontendTool.cpp:0:0
#30 0x000055f385de3863 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) (/usr/bin/swift-frontend+0xf41863)
#31 0x000055f385b6e51a swift::mainEntry(int, char const**) (/usr/bin/swift-frontend+0xccc51a)
#32 0x00007ff1a767f1ca (/lib/x86_64-linux-gnu/libc.so.6+0x2a1ca)
#33 0x00007ff1a767f28b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28b)
#34 0x000055f385b6d515 _start (/usr/bin/swift-frontend+0xccb515)
error: fatalError

Expected behavior

No crash.

Environment

Official Docker image of swiftlang/swift:nightly-6.2-noble. Have not tried on macOS.

Additional information

No response

[jamieQ]

looks like it hits the same issue on macOS (15.5). swift version:

Apple Swift version 6.2-dev (LLVM 92e60fa736d5709, Swift eba3593d16ab01c)
Target: arm64-apple-macosx15.0

[nate-chandler]

Fixed by #83624 .

[MahdiBM]

This is still (or again) happening in release builds (at least), using Swift 6.2 release.
Reproducible on macos 26 with swift test -c release. Branch vapor/penny-bot#370 is what I'm currently using.

https://github.com/vapor/penny-bot/actions/runs/17835885913/job/50712862880?pr=370

[MahdiBM]

May I know a temporary solution to this issue? So I can make sure we can move on, while you're working on a fix (hopefully for 6.2.1).

[nate-chandler]

A workaround is to mark the function (DiscordGateway.DiscordCache.(handleEvent in _6775718AF35C566C334CDE3CB8BA8CFC)(DiscordModels.Gateway.Event) -> ()) @_optimize(none).

[nate-chandler]

This is still (or again) happening in release builds (at least), using Swift 6.2 release.
Reproducible on macos 26 with swift test -c release. Branch vapor/penny-bot#370 is what I'm currently using.

The fix is not on this branch.

[MahdiBM]

So if I understand correctly, it is expected that Swift 6.2 has this bug? And solved in e.g. 6.3?

[MahdiBM]

Hmm I mean that's fine by me at this point, but it does sound weird. DiscordBM doesn't touch anything of those new "~Escapable"/"Lifetime annotations" or "~Copyable" stuff. So basically DiscordBM has compilation issues that it didn't have before, with no changes on its part.

[nate-chandler]

If there are any issues with building with recent main or the workaround doesn't work for you, please post here.