Compiler crash when using typed throws of an enum nested within a generic type

[TeamPuzel]

Description

A completely normal class is crashing with @MainActor applied.

Reproduction

@MainActor
public final class DrawObject<V: Vertex> {
    fileprivate let window: Window
    fileprivate let handle: UInt32
    public let texture: Texture
    public var mesh: Mesh<V>
    
    init(_ window: Window, texture: Texture, mesh: Mesh<V>) throws(InitError) {
        precondition(window === texture.window)
        self.texture = texture
        self.mesh = mesh
        
        var handle: UInt32 = 0
        glad_glGenBuffers(1, &handle)
        guard handle != 0 else { throw .creatingBuffer }
        self.handle = handle
    }
    
    public func bind() {
        
    }
    
    public func unbind() {
        
    }
    
    public enum InitError: Error {
        case creatingBuffer
    }
}

Don't know what is causing this exactly but this is the init mentioned in the crash message

Stack dump

warning: prohibited flag(s): -D_THREAD_SAFE
Building for debugging...
error: compile command failed due to signal 6 (use -v to see invocation)
Assertion failed: (destErrorType == SILType::getExceptionType(getASTContext())), function emitThrow, file SILGenStmt.cpp, line 1634.
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.	Program arguments: /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-05-14-a.xctoolchain/usr/bin/swift-frontend -frontend -c /Users/teampuzel/Games/Minecraft/src/Core/Graphics/Builtin.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/Color.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/Drawable.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/Image.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/Layout.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/MutableDrawable.swift /Users/teampuzel/Games/Minecraft/src/Core/Graphics/TGA.swift /Users/teampuzel/Games/Minecraft/src/Core/Math/Matrix.swift /Users/teampuzel/Games/Minecraft/src/Core/Math/Noise.swift /Users/teampuzel/Games/Minecraft/src/Core/Math/Utility.swift /Users/teampuzel/Games/Minecraft/src/Core/Math/Vector.swift /Users/teampuzel/Games/Minecraft/src/Core/Platform/Desktop/Mesh.swift -primary-file /Users/teampuzel/Games/Minecraft/src/Core/Platform/Desktop/OpenGL.swift -primary-file /Users/teampuzel/Games/Minecraft/src/Core/Platform/Input.swift /Users/teampuzel/Games/Minecraft/src/Core/Platform/Timer.swift /Users/teampuzel/Games/Minecraft/src/Game/Block.swift /Users/teampuzel/Games/Minecraft/src/Game/Chunk.swift /Users/teampuzel/Games/Minecraft/src/Game/Entity.swift /Users/teampuzel/Games/Minecraft/src/Game/World.swift /Users/teampuzel/Games/Minecraft/src/Main.swift -emit-dependencies-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/OpenGL.d -emit-reference-dependencies-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/OpenGL.swiftdeps -emit-dependencies-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/Input.d -emit-reference-dependencies-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/Input.swiftdeps -target arm64-apple-macosx14.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -sdk /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.4.sdk -I /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Modules -I /opt/homebrew/include -I /opt/homebrew/include/SDL2 -I /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/lib -F /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -color-diagnostics -enable-testing -g -debug-info-format=dwarf -dwarf-version=4 -module-cache-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/ModuleCache -swift-version 5 -Onone -D SWIFT_PACKAGE -D DEBUG -entry-point-function-name Minecraft_main -enable-upcoming-feature ExistentialAny -empty-abi-descriptor -Xcc -working-directory -Xcc /Users/teampuzel/Games/Minecraft -resource-dir /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-05-14-a.xctoolchain/usr/lib/swift -enable-anonymous-context-mangled-names -file-compilation-dir /Users/teampuzel/Games/Minecraft -Xcc -fmodule-map-file=/Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Assets.build/module.modulemap -Xcc -I -Xcc /Users/teampuzel/Games/Minecraft/assets/module/include -Xcc -fmodule-map-file=/Users/teampuzel/Games/Minecraft/lib/glad/include/module.modulemap -Xcc -I -Xcc /Users/teampuzel/Games/Minecraft/lib/glad/include -Xcc -fmodule-map-file=/Users/teampuzel/Games/Minecraft/sys/module.modulemap -Xcc -isysroot -Xcc /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.4.sdk -Xcc -F -Xcc /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -Xcc -fPIC -Xcc -g -module-name Minecraft -package-name minecraft -plugin-path /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-05-14-a.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-05-14-a.xctoolchain/usr/local/lib/swift/host/plugins -target-sdk-version 14.4 -target-sdk-name macosx14.4 -external-plugin-path /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/lib/swift/host/plugins#/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -external-plugin-path /Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/local/lib/swift/host/plugins#/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/usr/bin/swift-plugin-server -o /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/OpenGL.swift.o -o /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/Minecraft.build/Input.swift.o -index-store-path /Users/teampuzel/Games/Minecraft/.build/arm64-apple-macosx/debug/index/store -index-system-modules
1.	Apple Swift version 6.0-dev (LLVM 3417addab6ff197, Swift d677b7c23fd6355)
2.	Compiling with effective version 5.10
3.	While evaluating request ASTLoweringRequest(Lowering AST to SIL for file "/Users/teampuzel/Games/Minecraft/src/Core/Platform/Desktop/OpenGL.swift")
4.	While silgen constructor initializer SIL function "@$s9Minecraft10DrawObjectC_7texture4meshACyxGAA6WindowC_AA7TextureCAA4MeshVyxGtAC9InitErrorOyx_GYKcfc".
 for 'init(_:texture:mesh:)' (at /Users/teampuzel/Games/Minecraft/src/Core/Platform/Desktop/OpenGL.swift:219:5)
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           0x00000001079c0a8c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x00000001079bf258 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x00000001079c10d4 SignalHandler(int) + 304
3  libsystem_platform.dylib 0x000000018f0c3584 _sigtramp + 56
4  libsystem_pthread.dylib  0x000000018f092c20 pthread_kill + 288
5  libsystem_c.dylib        0x000000018ef9fa30 abort + 180
6  libsystem_c.dylib        0x000000018ef9ed20 err + 0
7  swift-frontend           0x0000000107b02598 swift::Lowering::SILGenFunction::emitThrow(swift::SILLocation, swift::Lowering::ManagedValue, bool) (.cold.16) + 0
8  swift-frontend           0x0000000102c569a4 swift::Lowering::SILGenFunction::emitThrow(swift::SILLocation, swift::Lowering::ManagedValue, bool) + 2380
9  swift-frontend           0x0000000102c53c24 swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 6128
10 swift-frontend           0x0000000102c535a8 swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 4468
11 swift-frontend           0x0000000102c528b4 swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 1152
12 swift-frontend           0x0000000102c535a8 swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 4468
13 swift-frontend           0x0000000102c52428 swift::Lowering::SILGenFunction::emitStmt(swift::Stmt*) + 24
14 swift-frontend           0x0000000102baf848 swift::Lowering::SILGenFunction::emitClassConstructorInitializer(swift::ConstructorDecl*) + 2488
15 swift-frontend           0x0000000102b64838 swift::Lowering::SILGenModule::emitFunctionDefinition(swift::SILDeclRef, swift::SILFunction*) + 2912
16 swift-frontend           0x0000000102b663b0 swift::Lowering::SILGenModule::emitOrDelayFunction(swift::SILDeclRef) + 252
17 swift-frontend           0x0000000102b67200 swift::Lowering::SILGenModule::emitConstructor(swift::ConstructorDecl*) + 388
18 swift-frontend           0x0000000102c63f68 (anonymous namespace)::SILGenType::emitType() + 336
19 swift-frontend           0x0000000102c63e0c swift::Lowering::SILGenModule::visitNominalTypeDecl(swift::NominalTypeDecl*) + 24
20 swift-frontend           0x0000000102b68cc8 swift::ASTLoweringRequest::evaluate(swift::Evaluator&, swift::ASTLoweringDescriptor) const + 880
21 swift-frontend           0x0000000102c51e80 swift::SimpleRequest<swift::ASTLoweringRequest, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>> (swift::ASTLoweringDescriptor), (swift::RequestFlags)9>::evaluateRequest(swift::ASTLoweringRequest const&, swift::Evaluator&) + 148
22 swift-frontend           0x0000000102b6e5e0 swift::ASTLoweringRequest::OutputType swift::Evaluator::getResultUncached<swift::ASTLoweringRequest, swift::ASTLoweringRequest::OutputType swift::evaluateOrFatal<swift::ASTLoweringRequest>(swift::Evaluator&, swift::ASTLoweringRequest)::'lambda'()>(swift::ASTLoweringRequest const&, swift::ASTLoweringRequest::OutputType swift::evaluateOrFatal<swift::ASTLoweringRequest>(swift::Evaluator&, swift::ASTLoweringRequest)::'lambda'()) + 340
23 swift-frontend           0x0000000102b695cc swift::performASTLowering(swift::FileUnit&, swift::Lowering::TypeConverter&, swift::SILOptions const&, swift::IRGenOptions const*) + 96
24 swift-frontend           0x00000001025517f8 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 580
25 swift-frontend           0x0000000102562ae8 withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 160
26 swift-frontend           0x0000000102553e64 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 708
27 swift-frontend           0x0000000102552dd0 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2384
28 swift-frontend           0x0000000102362ddc swift::mainEntry(int, char const**) + 3096
29 dyld                     0x000000018ed0a0e0 start + 2360

Expected behavior

I was writing a class and the lsp stopped working, I tried building from the command line expecting it to work and it crashed.

Environment

Apple Swift version 6.0-dev (LLVM 3417addab6ff197, Swift d677b7c)
Target: arm64-apple-macosx14.0

Additional information

No response

[TeamPuzel]

I tried removing the generics using [any Vertex] for the mesh and then it compiles, but even ignoring the cost this is a buffer I have to pass to OpenGL so it's not a usable workaround

Ok after trying various things it is probably actually unrelated to the MainActor annotation (although it seemed to work without it once?), rather a combination of the generic type with a nested error enum used together with typed throws. Removing the typed throw, moving the enum outside or removing generics all avoid this crash.