Using public App Store release of Xcode 12.0 (12A7209) and Swift 5.3, The compiler crashes while processing SwiftShell.
1. Apple Swift version 5.3 (swiftlang-1200.0.29.2 clang-1200.0.30.1)
2. While evaluating request TypeCheckSourceFileRequest(source_file "/<redacted>/.build/checkouts/SwiftShell/Sources/SwiftShell/Stream/Stream.swift")
3. While type-checking 'FileHandleStream' (at /<redacted>/.build/checkouts/SwiftShell/Sources/SwiftShell/Stream/Stream.swift:207:8)
4. While type-checking protocol conformance to 'TextOutputStreamable' (in module 'Swift') for type 'FileHandleStream' (declared at [/<redacted>/.build/checkouts/SwiftShell/Sources/SwiftShell/Stream/Stream.swift:207:8 - line:215:1] RangeText="class FileHandleStream: ReadableStream, WritableStream {
public let filehandle: FileHandle
public var encoding: String.Encoding
public init(_ filehandle: FileHandle, encoding: String.Encoding) {
self.filehandle = filehandle
self.encoding = encoding
}
")
0 swift 0x0000000105743865 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37
1 swift 0x0000000105742865 llvm::sys::RunSignalHandlers() + 85
2 swift 0x0000000105743e1f SignalHandler(int) + 111
3 libsystem_platform.dylib 0x00007fff7017b5fd _sigtramp + 29
4 libsystem_platform.dylib 000000000000000000 _sigtramp + 18446603338635561504
5 swift 0x0000000101fea0fb swift::constraints::ConstraintSystem::simplifyRestrictedConstraint(swift::constraints::ConversionRestrictionKind, swift::Type, swift::Type, swift::constraints::ConstraintKind, swift::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 779
6 swift 0x0000000101fd9c80 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::ConstraintKind, swift::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 14960
7 swift 0x0000000101fe4ec1 swift::constraints::ConstraintSystem::repairFailures(swift::Type, swift::Type, swift::constraints::ConstraintKind, llvm::SmallVectorImpl<swift::constraints::RestrictionOrFix>&, swift::constraints::ConstraintLocatorBuilder) + 12529
8 swift 0x0000000101fd9c15 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::ConstraintKind, swift::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 14853
9 swift 0x0000000101fda039 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::ConstraintKind, swift::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 15913
10 swift 0x0000000101ffeaa0 swift::constraints::ConstraintSystem::addConstraintImpl(swift::constraints::ConstraintKind, swift::Type, swift::Type, swift::constraints::ConstraintLocatorBuilder, bool) + 96
11 swift 0x0000000101fd5b42 swift::constraints::ConstraintSystem::addConstraint(swift::constraints::ConstraintKind, swift::Type, swift::Type, swift::constraints::ConstraintLocatorBuilder, bool) + 66
12 swift 0x00000001022069bd llvm::Optional<swift::RequirementMatch> llvm::function_ref<llvm::Optional<swift::RequirementMatch> (swift::Type, swift::Type)>::callback_fn<swift::matchWitness(llvm::DenseMap<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*>, swift::RequirementEnvironment, llvm::DenseMapInfo<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*> >, llvm::detail::DenseMapPair<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*>, swift::RequirementEnvironment> >&, swift::ProtocolDecl*, swift::ProtocolConformance*, swift::DeclContext*, swift::ValueDecl*, swift::ValueDecl*)::$_1>(long, swift::Type, swift::Type) + 93
13 swift 0x00000001021e7dca swift::matchWitness(swift::DeclContext*, swift::ValueDecl*, swift::ValueDecl*, llvm::function_ref<std::__1::tuple<llvm::Optional<swift::RequirementMatch>, swift::Type, swift::Type> ()>, llvm::function_ref<llvm::Optional<swift::RequirementMatch> (swift::Type, swift::Type)>, llvm::function_ref<swift::RequirementMatch (bool, llvm::ArrayRef<swift::OptionalAdjustment>)>) + 8778
14 swift 0x00000001021e9903 swift::matchWitness(llvm::DenseMap<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*>, swift::RequirementEnvironment, llvm::DenseMapInfo<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*> >, llvm::detail::DenseMapPair<std::__1::pair<swift::GenericSignatureImpl const*, swift::ClassDecl const*>, swift::RequirementEnvironment> >&, swift::ProtocolDecl*, swift::ProtocolConformance*, swift::DeclContext*, swift::ValueDecl*, swift::ValueDecl*) + 1187
15 swift 0x00000001021ea452 swift::WitnessChecker::findBestWitness(swift::ValueDecl*, bool*, swift::NormalProtocolConformance*, llvm::SmallVectorImpl<swift::RequirementMatch>&, unsigned int&, unsigned int&, bool&) + 946
16 swift 0x00000001021f4ac3 swift::ConformanceChecker::resolveWitnessViaLookup(swift::ValueDecl*) + 643
17 swift 0x00000001021ef9a5 swift::MultiConformanceChecker::checkIndividualConformance(swift::NormalProtocolConformance*, bool) + 14773
18 swift 0x00000001021eba93 swift::MultiConformanceChecker::checkAllConformances() + 147
19 swift 0x00000001021fb617 swift::TypeChecker::checkConformancesInContext(swift::DeclContext*, swift::IterableDeclContext*) + 8295
20 swift 0x00000001021ab89a (anonymous namespace)::DeclChecker::visitClassDecl(swift::ClassDecl*) + 8138
21 swift 0x00000001021a3d93 (anonymous namespace)::DeclChecker::visit(swift::Decl*) + 2739
22 swift 0x000000010226b621 swift::TypeCheckSourceFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 753
23 swift 0x000000010226e4a9 llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::getResultUncached<swift::TypeCheckSourceFileRequest>(swift::TypeCheckSourceFileRequest const&) + 953
24 swift 0x000000010226b1a4 swift::TypeCheckSourceFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckSourceFileRequest>(swift::Evaluator&, swift::TypeCheckSourceFileRequest, swift::TypeCheckSourceFileRequest::OutputType) + 164
25 swift 0x00000001013e655b swift::CompilerInstance::performSemaUpTo(swift::SourceFile::ASTStage_t) + 6859
26 swift 0x00000001012a72fd swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 6845
27 swift 0x000000010122bc07 main + 1255
28 libdyld.dylib 0x00007fff6ff82cc9 start + 1
29 libdyld.dylib 0x000000000000003c start + 18446603338637628276
I'm just starting to look in to this. But, I'm posting here for additional comments in case someone else finds a work around before I do.
Using public App Store release of Xcode 12.0 (12A7209) and Swift 5.3, The compiler crashes while processing SwiftShell.