Thank you for replying! For the specific example in the first post, I'm getting an Abort trap: 6
and a "Bad base type" failed assertion at lib/AST/Type.cpp#L4063
:
Contents of the error
Assertion failed: (0 && "Bad base type"), function getContextSubstitutions, file /Users/buildnode/jenkins/workspace/oss-swift-package-macos/swift/lib/AST/Type.cpp, line 4063.
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project and the crash backtrace.
Stack dump:
0. Program arguments: /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2021-01-19-a.xctoolchain/usr/bin/swift-frontend -frontend -c -primary-file /Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift /Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/Length.swift -emit-module-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main~partial.swiftmodule -emit-module-doc-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main~partial.swiftdoc -emit-module-source-info-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main~partial.swiftsourceinfo -serialize-diagnostics-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main.dia -emit-dependencies-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main.d -emit-reference-dependencies-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main.swiftdeps -target x86_64-apple-macos11.1 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk -I /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Products/Debug -F /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Products/Debug -enable-testing -g -module-cache-path /Users/xalien95/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -swift-version 5 -enforce-exclusivity=checked -Onone -D DEBUG -serialize-debugging-options -enable-anonymous-context-mangled-names -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/CommandLineTesting-generated-files.hmap -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/CommandLineTesting-own-target-headers.hmap -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/CommandLineTesting-all-target-headers.hmap -Xcc -iquote -Xcc /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/CommandLineTesting-project-headers.hmap -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Products/Debug/include -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/DerivedSources-normal/x86_64 -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/DerivedSources/x86_64 -Xcc -I/Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/DerivedSources -Xcc -DDEBUG=1 -Xcc -working-directory/Users/xalien95/Downloads/CommandLineTesting -target-sdk-version 11.1 -module-name CommandLineTesting -o /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Build/Intermediates.noindex/CommandLineTesting.build/Debug/CommandLineTesting.build/Objects-normal/x86_64/main.o -index-store-path /Users/xalien95/Library/Developer/Xcode/DerivedData/CommandLineTesting-bxncsogedvbhvtalcusdpuhhherx/Index/DataStore -index-system-modules
1. Apple Swift version 5.4-dev (LLVM a9b8270702a974a, Swift 1d7d28206555caf)
2. While evaluating request TypeCheckSourceFileRequest(source_file "/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift")
3. While type-checking 'S' (at /Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:20:1)
4. While evaluating request StoredPropertiesRequest(CommandLineTesting.(file).S@/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:20:8)
5. While evaluating request PropertyWrapperBackingPropertyInfoRequest(CommandLineTesting.(file).S.x@/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:21:10)
6. While evaluating request PropertyWrapperBackingPropertyTypeRequest(CommandLineTesting.(file).S.x@/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:21:10)
7. While evaluating request InterfaceTypeRequest(CommandLineTesting.(file).S.x@/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:21:10)
8. While evaluating request NamingPatternRequest(CommandLineTesting.(file).S.x@/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:21:10)
9. While evaluating request PatternBindingEntryRequest((unknown decl), 0)
10. While type-checking expression at [/Users/xalien95/Downloads/CommandLineTesting/CommandLineTesting/main.swift:21:4 - line:21:14] RangeText="A var x = "
0 swift-frontend 0x0000000104db79b5 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37
1 swift-frontend 0x0000000104db6c15 llvm::sys::RunSignalHandlers() + 85
2 swift-frontend 0x0000000104db7f86 SignalHandler(int) + 262
3 libsystem_platform.dylib 0x00007fff20357d7d _sigtramp + 29
4 swift-frontend 0x000000010134f900 swift::constraints::ConstraintSystem::addOverloadSet(llvm::ArrayRef<swift::constraints::Constraint*>, swift::constraints::ConstraintLocator*) + 128
5 libsystem_c.dylib 0x00007fff20266720 abort + 120
6 libsystem_c.dylib 0x00007fff202659d6 err + 0
7 swift-frontend 0x000000010535c9e3 swift::TypeBase::getContextSubstitutions(swift::DeclContext const*, swift::GenericEnvironment*) (.cold.15) + 35
8 swift-frontend 0x00000001018ee5b0 swift::TypeBase::getContextSubstitutions(swift::DeclContext const*, swift::GenericEnvironment*) + 1440
9 swift-frontend 0x00000001018ee73c swift::TypeBase::getMemberSubstitutions(swift::ValueDecl const*, swift::GenericEnvironment*) + 124
10 swift-frontend 0x00000001018eead7 swift::TypeBase::getTypeOfMember(swift::ModuleDecl*, swift::ValueDecl const*, swift::Type) + 359
11 swift-frontend 0x0000000101290677 generateWrappedPropertyTypeConstraints(swift::constraints::ConstraintSystem&, swift::Type, swift::VarDecl*, swift::Type) + 743
12 swift-frontend 0x000000010128f6b4 swift::constraints::ConstraintSystem::generateConstraints(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 2100
13 swift-frontend 0x00000001012e38b2 swift::constraints::ConstraintSystem::solveImpl(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 370
14 swift-frontend 0x00000001012e321a swift::constraints::ConstraintSystem::solve(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 106
15 swift-frontend 0x00000001013f9f23 swift::TypeChecker::typeCheckExpression(swift::constraints::SolutionApplicationTarget&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 531
16 swift-frontend 0x00000001013fa340 swift::TypeChecker::typeCheckBinding(swift::Pattern*&, swift::Expr*&, swift::DeclContext*, swift::Type, swift::PatternBindingDecl*, unsigned int) + 112
17 swift-frontend 0x00000001013fa5bb swift::TypeChecker::typeCheckPatternBinding(swift::PatternBindingDecl*, unsigned int, swift::Type) + 363
18 swift-frontend 0x00000001014b79aa swift::PatternBindingEntryRequest::evaluate(swift::Evaluator&, swift::PatternBindingDecl*, unsigned int) const + 650
19 swift-frontend 0x00000001014e879a llvm::Expected<swift::PatternBindingEntryRequest::OutputType> swift::Evaluator::getResultUncached<swift::PatternBindingEntryRequest>(swift::PatternBindingEntryRequest const&) + 426
20 swift-frontend 0x00000001014e8517 llvm::Expected<swift::PatternBindingEntryRequest::OutputType> swift::Evaluator::getResultCached<swift::PatternBindingEntryRequest, (void*)0>(swift::PatternBindingEntryRequest const&) + 119
21 swift-frontend 0x00000001014e3eb6 swift::PatternBindingEntryRequest::OutputType swift::evaluateOrDefault<swift::PatternBindingEntryRequest>(swift::Evaluator&, swift::PatternBindingEntryRequest, swift::PatternBindingEntryRequest::OutputType) + 54
22 swift-frontend 0x000000010140b218 swift::NamingPatternRequest::evaluate(swift::Evaluator&, swift::VarDecl*) const + 120
23 swift-frontend 0x00000001017c22b1 llvm::Expected<swift::NamingPatternRequest::OutputType> swift::Evaluator::getResultUncached<swift::NamingPatternRequest>(swift::NamingPatternRequest const&) + 417
24 swift-frontend 0x00000001017c2037 llvm::Expected<swift::NamingPatternRequest::OutputType> swift::Evaluator::getResultCached<swift::NamingPatternRequest, (void*)0>(swift::NamingPatternRequest const&) + 119
25 swift-frontend 0x000000010174f6d3 swift::NamingPatternRequest::OutputType swift::evaluateOrDefault<swift::NamingPatternRequest>(swift::Evaluator&, swift::NamingPatternRequest, swift::NamingPatternRequest::OutputType) + 51
26 swift-frontend 0x000000010140a881 swift::InterfaceTypeRequest::evaluate(swift::Evaluator&, swift::ValueDecl*) const + 593
27 swift-frontend 0x00000001017838c1 llvm::Expected<swift::InterfaceTypeRequest::OutputType> swift::Evaluator::getResultUncached<swift::InterfaceTypeRequest>(swift::InterfaceTypeRequest const&) + 417
28 swift-frontend 0x0000000101783647 llvm::Expected<swift::InterfaceTypeRequest::OutputType> swift::Evaluator::getResultCached<swift::InterfaceTypeRequest, (void*)0>(swift::InterfaceTypeRequest const&) + 119
29 swift-frontend 0x00000001017424e3 swift::InterfaceTypeRequest::OutputType swift::evaluateOrDefault<swift::InterfaceTypeRequest>(swift::Evaluator&, swift::InterfaceTypeRequest, swift::InterfaceTypeRequest::OutputType) + 51
30 swift-frontend 0x0000000101737c20 swift::ValueDecl::getInterfaceType() const + 64
31 swift-frontend 0x00000001014646d2 swift::PropertyWrapperBackingPropertyTypeRequest::evaluate(swift::Evaluator&, swift::VarDecl*) const + 162
32 swift-frontend 0x00000001017ccdf1 llvm::Expected<swift::PropertyWrapperBackingPropertyTypeRequest::OutputType> swift::Evaluator::getResultUncached<swift::PropertyWrapperBackingPropertyTypeRequest>(swift::PropertyWrapperBackingPropertyTypeRequest const&) + 417
33 swift-frontend 0x00000001017ccb1e llvm::Expected<swift::PropertyWrapperBackingPropertyTypeRequest::OutputType> swift::Evaluator::getResultCached<swift::PropertyWrapperBackingPropertyTypeRequest, (void*)0>(swift::PropertyWrapperBackingPropertyTypeRequest const&) + 414
34 swift-frontend 0x0000000101750780 swift::PropertyWrapperBackingPropertyTypeRequest::OutputType swift::evaluateOrDefault<swift::PropertyWrapperBackingPropertyTypeRequest>(swift::Evaluator&, swift::PropertyWrapperBackingPropertyTypeRequest, swift::PropertyWrapperBackingPropertyTypeRequest::OutputType) + 64
35 swift-frontend 0x00000001014ba652 swift::PropertyWrapperBackingPropertyInfoRequest::evaluate(swift::Evaluator&, swift::VarDecl*) const + 34
36 swift-frontend 0x00000001014aa651 swift::SimpleRequest<swift::PropertyWrapperBackingPropertyInfoRequest, swift::PropertyWrapperBackingPropertyInfo (swift::VarDecl*), (swift::RequestFlags)2>::evaluateRequest(swift::PropertyWrapperBackingPropertyInfoRequest const&, swift::Evaluator&) + 17
37 swift-frontend 0x00000001017cf11e llvm::Expected<swift::PropertyWrapperBackingPropertyInfoRequest::OutputType> swift::Evaluator::getResultUncached<swift::PropertyWrapperBackingPropertyInfoRequest>(swift::PropertyWrapperBackingPropertyInfoRequest const&) + 430
38 swift-frontend 0x00000001017cee15 llvm::Expected<swift::PropertyWrapperBackingPropertyInfoRequest::OutputType> swift::Evaluator::getResultCached<swift::PropertyWrapperBackingPropertyInfoRequest, (void*)0>(swift::PropertyWrapperBackingPropertyInfoRequest const&) + 485
39 swift-frontend 0x0000000101750960 swift::PropertyWrapperBackingPropertyInfoRequest::OutputType swift::evaluateOrDefault<swift::PropertyWrapperBackingPropertyInfoRequest>(swift::Evaluator&, swift::PropertyWrapperBackingPropertyInfoRequest, swift::PropertyWrapperBackingPropertyInfoRequest::OutputType) + 64
40 swift-frontend 0x0000000101750d16 swift::VarDecl::getPropertyWrapperBackingProperty() const + 102
41 swift-frontend 0x00000001014b71e2 computeLoweredStoredProperties(swift::NominalTypeDecl*) + 162
42 swift-frontend 0x00000001014b6e02 swift::StoredPropertiesRequest::evaluate(swift::Evaluator&, swift::NominalTypeDecl*) const + 162
43 swift-frontend 0x0000000101786eeb llvm::Expected<swift::StoredPropertiesRequest::OutputType> swift::Evaluator::getResultUncached<swift::StoredPropertiesRequest>(swift::StoredPropertiesRequest const&) + 427
44 swift-frontend 0x0000000101786c02 llvm::Expected<swift::StoredPropertiesRequest::OutputType> swift::Evaluator::getResultCached<swift::StoredPropertiesRequest, (void*)0>(swift::StoredPropertiesRequest const&) + 434
45 swift-frontend 0x00000001017458d8 swift::StoredPropertiesRequest::OutputType swift::evaluateOrDefault<swift::StoredPropertiesRequest>(swift::Evaluator&, swift::StoredPropertiesRequest, swift::StoredPropertiesRequest::OutputType) + 56
46 swift-frontend 0x000000010142f363 swift::ASTVisitor<(anonymous namespace)::DeclChecker, void, void, void, void, void, void>::visit(swift::Decl*) + 1427
47 swift-frontend 0x000000010142e5ef (anonymous namespace)::DeclChecker::visit(swift::Decl*) + 159
48 swift-frontend 0x000000010142e532 swift::TypeChecker::typeCheckDecl(swift::Decl*) + 130
49 swift-frontend 0x00000001014e3778 swift::TypeCheckSourceFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 184
50 swift-frontend 0x00000001014e474d llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::getResultUncached<swift::TypeCheckSourceFileRequest>(swift::TypeCheckSourceFileRequest const&) + 429
51 swift-frontend 0x00000001014e44d2 llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::getResultCached<swift::TypeCheckSourceFileRequest, (void*)0>(swift::TypeCheckSourceFileRequest const&) + 114
52 swift-frontend 0x00000001014e35be swift::TypeCheckSourceFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckSourceFileRequest>(swift::Evaluator&, swift::TypeCheckSourceFileRequest, swift::TypeCheckSourceFileRequest::OutputType) + 46
53 swift-frontend 0x0000000100717fea swift::CompilerInstance::forEachFileToTypeCheck(llvm::function_ref<void (swift::SourceFile&)>) + 90
54 swift-frontend 0x0000000100717eda swift::CompilerInstance::performSema() + 74
55 swift-frontend 0x00000001005f18f3 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 5091
56 swift-frontend 0x000000010058dc32 main + 866
57 libdyld.dylib 0x00007fff2032e621 start + 1
58 libdyld.dylib 0x000000000000004a start + 18446603339975957034
error: Abort trap: 6 (in target 'CommandLineTesting' from project 'CommandLineTesting')
So the answer to my question is "no, it's not normal for a development snapshot to have the type checker to abort the build process and you should file a bug"?