[SR-7674] Compiler crash while working on a type erasurer

[swift-ci]

Previous ID	SR-7674
Radar	None
Original Reporter	guidomb (JIRA User)
Type	Bug

Attachment: Download

Environment

Xcode Version 9.3 (9E145)

macOS Version 10.13.4 (17E202)

ReactiveSwift 3.1.0 revision 46fb4d4a8285286e54929add1d12f384675895c6

Result 3.2.4 revision 7477584259bfce2560a19e06ad9f71db441fff11

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, CompilerCrash
Assignee	None
Priority	Medium

md5: b6710c796fab2d8226271de84635e7dc

Issue Description:

The following code generates a compiler crash

import Foundation
import ReactiveSwift
import Result

protocol BehaviorEffectPerformer {

    associatedtype EffectType
    associatedtype EffectResponseType
    associatedtype EffectErrorType: Error

    typealias EffectResult = Result<EffectResponseType, EffectErrorType>
    typealias EffectResultProducer = SignalProducer<EffectResult, NoError>

    func perform(effect: EffectType) -> EffectResultProducer

}

struct AnyBehaviorEffectPerformer<EffectType, EffectResponseType, EffectErrorType: Error>: BehaviorEffectPerformer {

    private let performEffect: (EffectType) -> EffectResultProducer

    init<BehaviorEffectPerformerType: BehaviorEffectPerformer>(_ effectPerformer: BehaviorEffectPerformerType)
        where   BehaviorEffectPerformerType.EffectType == EffectType,
                BehaviorEffectPerformerType.EffectResponseType == EffectResponseType,
                BehaviorEffectPerformerType.EffectErrorType ==EffectErrorType {
        self.performEffect = effectPerformer.perform(effect:)
    }

    func perform(effect: EffectType) -> EffectResultProducer {
        return performEffect
    }

}

Compiler output:

CompileSwift normal x86_64 /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/File.swift
    cd /Users/guidomb/Documents/projects/wolox/Feebi
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Behaviors/CreateSurvey.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/OutputRenderer.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/Services/GoogleAuth.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/BotBehaviorRunner.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Behavior.swift -primary-file /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/File.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/Services/SlackService.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/main.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/JobExecutor.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Effector.swift -target x86_64-apple-macosx10.10 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -I /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug -F /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug -F /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -g -module-cache-path /Users/guidomb/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -swift-version 4 -enforce-exclusivity=checked -Onone -D SWIFT_PACKAGE -D Xcode -serialize-debugging-options -Xcc -fmodule-map-file=/Users/guidomb/Documents/projects/wolox/Feebi/Feebi.xcodeproj/GeneratedModuleMap/CHTTPParser/module.modulemap -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/swift-overrides.hmap -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug/include -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/common-crypto-spm--132958532151328779 -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/zlib-spm.git-7042465659040932026 -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/http-5976992940601425903/Sources/CHTTPParser/include -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/Feebi.xcodeproj/GeneratedModuleMap/CHTTPParser -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/DerivedSources/x86_64 -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/DerivedSources -Xcc -working-directory/Users/guidomb/Documents/projects/wolox/Feebi -emit-module-doc-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File~partial.swiftdoc -serialize-diagnostics-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.dia -module-name Feebi -emit-module-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File~partial.swiftmodule -emit-dependencies-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.d -emit-reference-dependencies-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.swiftdeps -o /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.o -index-store-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Index/DataStore -index-system-modules

0  swift                    0x00000001058f3ffa PrintStackTraceSignalHandler(void*) + 42
1  swift                    0x00000001058f33b6 SignalHandler(int) + 966
2  libsystem_platform.dylib 0x00007fff743cff5a _sigtramp + 26
3  libsystem_platform.dylib 0x00007fe6820fa8c0 _sigtramp + 231909760
4  swift                    0x0000000102d67cb5 swift::Lowering::TypeConverter::getConstantInfo(swift::SILDeclRef) + 117
5  swift                    0x0000000102d8cf3b swift::SILModule::getOrCreateFunction(swift::SILLocation, swift::SILDeclRef, swift::ForDefinition_t, swift::ProfileCounter) + 91
6  swift                    0x0000000102800545 swift::Lowering::SILGenModule::getFunction(swift::SILDeclRef, swift::ForDefinition_t) + 325
7  swift                    0x0000000102801ca1 swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 721
8  swift                    0x00000001028eb3f3 (anonymous namespace)::SILGenType::emitType() + 819
9  swift                    0x000000010280bba6 swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visit(swift::Decl*) + 70
10 swift                    0x000000010280acdb swift::Lowering::SILGenModule::emitSourceFile(swift::SourceFile*, unsigned int) + 1371
11 swift                    0x000000010280c8c1 swift::SILModule::constructSIL(swift::ModuleDecl*, swift::SILOptions&, swift::FileUnit*, llvm::Optional<unsigned int>, bool) + 865
12 swift                    0x0000000101f513bc performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 27340
13 swift                    0x0000000101f48e64 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 7908
14 swift                    0x0000000101efd8b5 main + 18917
15 libdyld.dylib            0x00007fff740c1015 start + 1
Stack dump:
0.    Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Behaviors/CreateSurvey.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/OutputRenderer.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/Services/GoogleAuth.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/BotBehaviorRunner.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Behavior.swift -primary-file /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/File.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/Services/SlackService.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/main.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/JobExecutor.swift /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/Effector.swift -target x86_64-apple-macosx10.10 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -I /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug -F /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug -F /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -g -module-cache-path /Users/guidomb/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -swift-version 4 -enforce-exclusivity=checked -Onone -D SWIFT_PACKAGE -D Xcode -serialize-debugging-options -Xcc -fmodule-map-file=/Users/guidomb/Documents/projects/wolox/Feebi/Feebi.xcodeproj/GeneratedModuleMap/CHTTPParser/module.modulemap -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/swift-overrides.hmap -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Products/Debug/include -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/common-crypto-spm--132958532151328779 -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/zlib-spm.git-7042465659040932026 -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/.build/checkouts/http-5976992940601425903/Sources/CHTTPParser/include -Xcc -I/Users/guidomb/Documents/projects/wolox/Feebi/Feebi.xcodeproj/GeneratedModuleMap/CHTTPParser -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/DerivedSources/x86_64 -Xcc -I/Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/DerivedSources -Xcc -working-directory/Users/guidomb/Documents/projects/wolox/Feebi -emit-module-doc-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File~partial.swiftdoc -serialize-diagnostics-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.dia -module-name Feebi -emit-module-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File~partial.swiftmodule -emit-dependencies-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.d -emit-reference-dependencies-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.swiftdeps -o /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Build/Intermediates.noindex/Feebi.build/Debug/Feebi.build/Objects-normal/x86_64/File.o -index-store-path /Users/guidomb/Library/Developer/Xcode/DerivedData/Feebi-fptzhdpcxzqcwreffszxemnslfki/Index/DataStore -index-system-modules 
1.    While emitting SIL for 'perform(effect:)' at /Users/guidomb/Documents/projects/wolox/Feebi/Sources/Feebi/BotBehaviors/File.swift:29:5

[swift-ci]

Comment by Guido Marucci Blas (JIRA)

OK I found a work-around, instead of declaring performEffect inside AnyBehaviorEffectPerformer as

private let performEffect: (EffectType) -> EffectResultProducer  

I declare it without using the typealias inherited from the protocol comformance to BehaviorEffectPerformer as

private let performEffect: (EffectType) -> SignalProducer<Result<EffectResponseType, EffectErrorType>, NoError>

and it compiled. Maybe something clashing when trying to expand the typealias?

[swift-ci]

Comment by Guido Marucci Blas (JIRA)

Here are swift build crash output for Swift version in Xcode 9.3 and latest 4.2 snapshot. I've also attached a project that reproduces the issue.

Apple Swift version 4.1 (swiftlang-902.0.48 clang-902.0.37.1)
Target: x86_64-apple-darwin17.5.0

Compile Swift Module 'Foo' (2 sources)
0  swift                    0x000000010d264ffa PrintStackTraceSignalHandler(void*) + 42
1  swift                    0x000000010d2643b6 SignalHandler(int) + 966
2  libsystem_platform.dylib 0x00007fff743cff5a _sigtramp + 26
3  libsystem_platform.dylib 0x00007ff448967300 _sigtramp + 3562632128
4  swift                    0x000000010a6d8cb5 swift::Lowering::TypeConverter::getConstantInfo(swift::SILDeclRef) + 117
5  swift                    0x000000010a6fdf3b swift::SILModule::getOrCreateFunction(swift::SILLocation, swift::SILDeclRef, swift::ForDefinition_t, swift::ProfileCounter) + 91
6  swift                    0x000000010a171545 swift::Lowering::SILGenModule::getFunction(swift::SILDeclRef, swift::ForDefinition_t) + 325
7  swift                    0x000000010a172ca1 swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 721
8  swift                    0x000000010a25c3f3 (anonymous namespace)::SILGenType::emitType() + 819
9  swift                    0x000000010a17cba6 swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visit(swift::Decl*) + 70
10 swift                    0x000000010a17bcdb swift::Lowering::SILGenModule::emitSourceFile(swift::SourceFile*, unsigned int) + 1371
11 swift                    0x000000010a17d8c1 swift::SILModule::constructSIL(swift::ModuleDecl*, swift::SILOptions&, swift::FileUnit*, llvm::Optional<unsigned int>, bool) + 865
12 swift                    0x00000001098c23bc performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 27340
13 swift                    0x00000001098b9e64 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 7908
14 swift                    0x000000010986e8b5 main + 18917
15 libdyld.dylib            0x00007fff740c1015 start + 1
16 libdyld.dylib            0x0000000000000027 start + 2348019731
Stack dump:
0.    Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c -primary-file /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/File.swift /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/main.swift -target x86_64-apple-macosx10.10 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -I /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug -F /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -enable-testing -g -module-cache-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/ModuleCache -swift-version 4 -Onone -D SWIFT_PACKAGE -color-diagnostics -emit-module-doc-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File~partial.swiftdoc -module-name Foo -emit-module-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File~partial.swiftmodule -emit-dependencies-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.d -emit-reference-dependencies-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.swiftdeps -num-threads 8 -o /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.swift.o 
1.    While emitting SIL for 'perform(effect:)' at /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/File.swift:32:5
<unknown>:0: error: unable to execute command: Segmentation fault: 11
<unknown>:0: error: compile command failed due to signal 11 (use -v to see invocation)
error: terminated(1): /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-build-tool -f /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/debug.yaml main output:

Apple Swift version 4.2-dev (LLVM ae60dc0632, Clang 91ee593a0d, Swift 9f28451)
Target: x86_64-apple-darwin17.5.0

Compile Swift Module 'Foo' (2 sources)
Assertion failed: ((HadError || !M.is<SourceFile*>() || M.get<SourceFile*>()->ASTStage < SourceFile::TypeChecked) && "UnresolvedDeclRef" "in wrong phase"), function walkToExprPre, file /Users/buildnode/jenkins/workspace/oss-swift-4.2-package-osx/swift/include/swift/AST/ExprNodes.def, line 90.
0  swift                    0x0000000108d4a068 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1  swift                    0x0000000108d4a776 SignalHandler(int) + 694
2  libsystem_platform.dylib 0x00007fff743cff5a _sigtramp + 26
3  libsystem_platform.dylib 0x00007ffeea6a00c8 _sigtramp + 1982661000
4  libsystem_c.dylib        0x00007fff7416d1ae abort + 127
5  libsystem_c.dylib        0x00007fff741351ac basename_r + 0
6  swift                    0x000000010672796a (anonymous namespace)::Verifier::walkToExprPre(swift::Expr*) + 1034
7  swift                    0x000000010673ce14 (anonymous namespace)::Traversal::visitApplyExpr(swift::ApplyExpr*) + 36
8  swift                    0x000000010673dc74 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 2996
9  swift                    0x000000010673d187 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 199
10 swift                    0x000000010673f755 (anonymous namespace)::Traversal::visitAbstractFunctionDecl(swift::AbstractFunctionDecl*) + 725
11 swift                    0x0000000106739da6 (anonymous namespace)::Traversal::doIt(swift::Decl*) + 310
12 swift                    0x000000010673efbb (anonymous namespace)::Traversal::visitNominalTypeDecl(swift::NominalTypeDecl*) + 475
13 swift                    0x0000000106739d98 (anonymous namespace)::Traversal::doIt(swift::Decl*) + 296
14 swift                    0x0000000106739c5b swift::Decl::walk(swift::ASTWalker&) + 27
15 swift                    0x00000001067e55ea swift::SourceFile::walk(swift::ASTWalker&) + 170
16 swift                    0x000000010672700b swift::verify(swift::SourceFile&) + 59
17 swift                    0x00000001064e578b swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int) + 2187
18 swift                    0x000000010611a7e2 swift::CompilerInstance::parseAndCheckTypes(swift::CompilerInstance::ImplicitImports const&) + 834
19 swift                    0x000000010611a068 swift::CompilerInstance::performSema() + 472
20 swift                    0x00000001055a4a20 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 1904
21 swift                    0x00000001055a32a6 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3318
22 swift                    0x000000010555f6ed main + 2317
23 libdyld.dylib            0x00007fff740c1015 start + 1
24 libdyld.dylib            0x0000000000000029 start + 2348019733
Stack dump:
0.    Program arguments: /Library/Developer/Toolchains/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-05-12-a.xctoolchain/usr/bin/swift -frontend -c -primary-file /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/File.swift /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/main.swift -emit-module-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File~partial.swiftmodule -emit-module-doc-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File~partial.swiftdoc -emit-dependencies-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.d -emit-reference-dependencies-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.swiftdeps -target x86_64-apple-macosx10.10 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -I /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug -F /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/Library/Frameworks -enable-testing -g -module-cache-path /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/ModuleCache -swift-version 4 -Onone -D SWIFT_PACKAGE -D DEBUG -color-diagnostics -module-name Foo -num-threads 8 -o /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/x86_64-apple-macosx10.10/debug/Foo.build/File.swift.o 
1.    While walking into decl 'AnyBehaviorEffectPerformer' at /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/File.swift:18:1
2.    While walking into body of 'perform(effect:)' at /Users/guidomb/Documents/projects/wolox/Feebi/Foo/Sources/Foo/File.swift:32:5
<unknown>:0: error: unable to execute command: Abort trap: 6
<unknown>:0: error: compile command failed due to signal 6 (use -v to see invocation)
error: terminated(1): /Library/Developer/Toolchains/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-05-12-a.xctoolchain/usr/bin/swift-build-tool -f /Users/guidomb/Documents/projects/wolox/Feebi/Foo/.build/debug.yaml main output:

[swift-ci]

Comment by Guido Marucci Blas (JIRA)

Here is a twitter thread were I discussed this in case there some replies that can help with this issue -> https://twitter.com/guidomb/status/995810518735753218

[belkadan]

@slavapestov, @rudkx, sound familiar?

[slavapestov]

I need to come up with a stand-alone test case, but the problem might even be with associated type inference.

[fibrechannelscsi]

I hit this today in our codebase:
Assertion failed: ((HadError || !M.is<SourceFile*>() || M.get<SourceFile*>()->ASTStage < SourceFile::TypeChecked) && "UnresolvedDot" "in wrong phase"), function walkToExprPre, file ExprNodes.def, line 104.
I don't have a reproducer yet.

[fibrechannelscsi]

Now that I look at it, this may be a different issue. If we look at ExprNodes.def, UnresolvedDeclRef used to be in line 90, but is now line 93.
I'm hitting UnresolvedDot in line 104 in the same file.