Open
Description
Description
The Swift compiler crashes during type checking when attempting to reference a typealias from a subclass of a generic class in Xcode 26 beta 1. This issue does not occur in Xcode 16, where the same code compiles without any problems.
Reproduction
class List<Row, Section> {
typealias ListFetchHandler = (_ url: URL) -> [String]
}
class SingleSectionList<Row>: List<Row, Never> {
}
// ❌ This function causes a compiler crash or error
func handler() -> SingleSectionList.ListFetchHandler {
return { url in
["Apple", "Banana", "Orange"]
}
}
// ✅ These versions work correctly:
// 1. Using base class directly
// func handler() -> List.ListFetchHandler {
// return { url in
// ["Apple", "Banana", "Orange"]
// }
// }
// 2. Providing concrete type argument
// func handler() -> SingleSectionList<Any>.ListFetchHandler {
// return { url in
// ["Apple", "Banana", "Orange"]
// }
// }Stack dump
Assertion failed: (isAdmissibleType(Second)), function Constraint at Constraint.cpp:65.
(to display assertion configuration options: -Xllvm -assert-help)
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0. Program arguments: /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/AppDelegate.swift /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/SceneDelegate.swift -primary-file /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources/GeneratedAssetSymbols.swift -emit-dependencies-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.d -emit-const-values-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.swiftconstvalues -emit-reference-dependencies-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.swiftdeps -serialize-diagnostics-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.dia -emit-localized-strings -emit-localized-strings-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64 -target arm64-apple-ios26.0-simulator -module-can-import-version DeveloperToolsSupport 23.0.4 23.0.4 -module-can-import-version SwiftUI 7.0.67.1 7.0.67 -module-can-import-version UIKit 9071.1.106 9071.1.106 -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libFoundationMacros.dylib#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#FoundationMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libObservationMacros.dylib#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#ObservationMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libPreviewsMacros.dylib#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#PreviewsMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftMacros.dylib#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#SwiftMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftUIMacros.dylib#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#SwiftUIMacros -disable-implicit-swift-modules -Xcc -fno-implicit-modules -Xcc -fno-implicit-module-maps -explicit-swift-module-map-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/SampleListApp-dependencies-31.json -Xllvm -aarch64-use-tbi -enable-objc-interop -sdk /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk -I /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator -F /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator -no-color-diagnostics -Xcc -fno-color-diagnostics -enable-testing -g -debug-info-format=dwarf -dwarf-version=5 -module-cache-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SwiftExplicitPrecompiledModules -swift-version 5 -enforce-exclusivity=checked -Onone -D DEBUG -serialize-debugging-options -const-gather-protocols-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/SampleListApp_const_extract_protocols.json -enable-upcoming-feature MemberImportVisibility -enable-experimental-feature DebugDescriptionMacro -enable-bare-slash-regex -default-isolation=MainActor -empty-abi-descriptor -validate-clang-modules-once -clang-build-session-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/Session.modulevalidation -Xcc -working-directory -Xcc /Users/pv-tharun/Documents/Playgrounds/SampleListApp -enable-anonymous-context-mangled-names -file-compilation-dir /Users/pv-tharun/Documents/Playgrounds/SampleListApp -Xcc -ivfsstatcache -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator26.0-23A5260k-6c77a32d7a732e459a5b0e258bab5d26.sdkstatcache -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-generated-files.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-own-target-headers.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-all-target-headers.hmap -Xcc -iquote -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-project-headers.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources-normal/arm64 -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources/arm64 -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources -Xcc -DDEBUG=1 -no-auto-bridging-header-chaining -module-name SampleListApp -frontend-parseable-output -disable-clang-spi -target-sdk-version 26.0 -target-sdk-name iphonesimulator26.0 -clang-target arm64-apple-ios26.0-simulator -o /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.o -index-unit-output-path /SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.o -index-store-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Index.noindex/DataStore -index-system-modules
1. Apple Swift version 6.2 (swiftlang-6.2.0.9.909 clang-1700.3.9.907)
2. Compiling with effective version 5.10
3. While evaluating request TypeCheckPrimaryFileRequest(source_file "/Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift")
4. While evaluating request TypeCheckFunctionBodyRequest(SampleListApp.(file).handler()@/Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift:23:6)
5. While type-checking statement at [/Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift:24:1 - line:28:1] RangeText="{
return { url in
["Apple", "Banana", "Orange"]
}
"
6. While type-checking statement at [/Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift:25:5 - line:27:5] RangeText="return { url in
["Apple", "Banana", "Orange"]
"
7. While type-checking-target starting at /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift:25:12
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 0x0000000108f5bcb0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1 swift-frontend 0x0000000108f59640 llvm::sys::RunSignalHandlers() + 112
2 swift-frontend 0x0000000108f5c2dc SignalHandler(int, __siginfo*, void*) + 344
3 libsystem_platform.dylib 0x0000000185d2c624 _sigtramp + 56
4 libsystem_pthread.dylib 0x0000000185cf288c pthread_kill + 296
5 libsystem_c.dylib 0x0000000185bfbc60 abort + 124
6 swift-frontend 0x0000000104822f54 ASSERT_failure(char const*, char const*, int, char const*) + 1720
7 swift-frontend 0x0000000103f06f20 swift::constraints::Constraint::create(swift::constraints::ConstraintSystem&, swift::constraints::ConstraintKind, swift::Type, swift::Type, swift::constraints::ConstraintLocator*, llvm::ArrayRef<swift::TypeVariableType*>) + 992
8 swift-frontend 0x0000000103e1dc38 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::ConstraintKind, swift::optionset::OptionSet<swift::constraints::ConstraintSystem::TypeMatchFlags, unsigned int>, swift::constraints::ConstraintLocatorBuilder) + 3348
9 swift-frontend 0x0000000103e54fc0 swift::constraints::ConstraintSystem::addConstraintImpl(swift::constraints::ConstraintKind, swift::Type, swift::Type, swift::constraints::ConstraintLocatorBuilder, bool) + 92
10 swift-frontend 0x0000000103e569e0 swift::constraints::ConstraintSystem::addContextualConversionConstraint(swift::Expr*, swift::Type, swift::ContextualTypePurpose, swift::constraints::ConstraintLocator*) + 728
11 swift-frontend 0x0000000103df3158 swift::constraints::ConstraintSystem::generateConstraints(swift::constraints::SyntacticElementTarget&, swift::FreeTypeVariableBinding) + 2352
12 swift-frontend 0x0000000103e6f018 swift::constraints::ConstraintSystem::solve(swift::constraints::SyntacticElementTarget&, swift::FreeTypeVariableBinding) + 144
13 swift-frontend 0x00000001040861e8 swift::TypeChecker::typeCheckTarget(swift::constraints::SyntacticElementTarget&, swift::optionset::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::DiagnosticTransaction*) + 704
14 swift-frontend 0x000000010419deec swift::ASTVisitor<(anonymous namespace)::StmtChecker, void, swift::Stmt*, void, void, void, void>::visit(swift::Stmt*) + 2896
15 swift-frontend 0x000000010419d264 bool (anonymous namespace)::StmtChecker::typeCheckStmt<swift::Stmt>(swift::Stmt*&) + 312
16 swift-frontend 0x0000000104197528 (anonymous namespace)::StmtChecker::typeCheckASTNode(swift::ASTNode&) + 80
17 swift-frontend 0x000000010419d4bc swift::ASTVisitor<(anonymous namespace)::StmtChecker, void, swift::Stmt*, void, void, void, void>::visit(swift::Stmt*) + 288
18 swift-frontend 0x000000010419ab1c bool (anonymous namespace)::StmtChecker::typeCheckStmt<swift::BraceStmt>(swift::BraceStmt*&) + 312
19 swift-frontend 0x000000010419961c swift::TypeCheckFunctionBodyRequest::evaluate(swift::Evaluator&, swift::AbstractFunctionDecl*) const + 3004
20 swift-frontend 0x00000001045f9d9c swift::TypeCheckFunctionBodyRequest::OutputType swift::Evaluator::getResultUncached<swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckFunctionBodyRequest>(swift::Evaluator&, swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType)::'lambda'()>(swift::TypeCheckFunctionBodyRequest const&, swift::TypeCheckFunctionBodyRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckFunctionBodyRequest>(swift::Evaluator&, swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType)::'lambda'()) + 688
21 swift-frontend 0x0000000104549f48 swift::AbstractFunctionDecl::getTypecheckedBody() const + 152
22 swift-frontend 0x00000001041f0094 swift::TypeCheckPrimaryFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 1008
23 swift-frontend 0x00000001041f6f6c swift::TypeCheckPrimaryFileRequest::OutputType swift::Evaluator::getResultUncached<swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckPrimaryFileRequest>(swift::Evaluator&, swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType)::'lambda'()>(swift::TypeCheckPrimaryFileRequest const&, swift::TypeCheckPrimaryFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckPrimaryFileRequest>(swift::Evaluator&, swift::TypeCheckPrimaryFileRequest, swift::TypeCheckPrimaryFileRequest::OutputType)::'lambda'()) + 672
24 swift-frontend 0x0000000102fba468 bool llvm::function_ref<bool (swift::SourceFile&)>::callback_fn<swift::CompilerInstance::performSema()::$_0>(long, swift::SourceFile&) + 156
25 swift-frontend 0x0000000102fb4a38 swift::CompilerInstance::forEachFileToTypeCheck(llvm::function_ref<bool (swift::SourceFile&)>) + 176
26 swift-frontend 0x0000000102fb48cc swift::CompilerInstance::performSema() + 120
27 swift-frontend 0x0000000102bd2d00 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 772
28 swift-frontend 0x0000000102bd1cfc swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3580
29 swift-frontend 0x0000000102b53390 swift::mainEntry(int, char const**) + 5412
30 dyld 0x0000000185952b98 start + 6076
Failed frontend command:
/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/AppDelegate.swift /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/SceneDelegate.swift -primary-file /Users/pv-tharun/Documents/Playgrounds/SampleListApp/SampleListApp/ViewController.swift /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources/GeneratedAssetSymbols.swift -emit-dependencies-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.d -emit-const-values-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.swiftconstvalues -emit-reference-dependencies-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.swiftdeps -serialize-diagnostics-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.dia -emit-localized-strings -emit-localized-strings-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64 -target arm64-apple-ios26.0-simulator -module-can-import-version DeveloperToolsSupport 23.0.4 23.0.4 -module-can-import-version SwiftUI 7.0.67.1 7.0.67 -module-can-import-version UIKit 9071.1.106 9071.1.106 -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libFoundationMacros.dylib\#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#FoundationMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libObservationMacros.dylib\#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#ObservationMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libPreviewsMacros.dylib\#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#PreviewsMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftMacros.dylib\#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#SwiftMacros -load-resolved-plugin /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftUIMacros.dylib\#/Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#SwiftUIMacros -disable-implicit-swift-modules -Xcc -fno-implicit-modules -Xcc -fno-implicit-module-maps -explicit-swift-module-map-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/SampleListApp-dependencies-31.json -Xllvm -aarch64-use-tbi -enable-objc-interop -sdk /Users/pv-tharun/Downloads/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk -I /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator -F /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator -no-color-diagnostics -Xcc -fno-color-diagnostics -enable-testing -g -debug-info-format\=dwarf -dwarf-version\=5 -module-cache-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SwiftExplicitPrecompiledModules -swift-version 5 -enforce-exclusivity\=checked -Onone -D DEBUG -serialize-debugging-options -const-gather-protocols-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/SampleListApp_const_extract_protocols.json -enable-upcoming-feature MemberImportVisibility -enable-experimental-feature DebugDescriptionMacro -enable-bare-slash-regex -default-isolation\=MainActor -empty-abi-descriptor -validate-clang-modules-once -clang-build-session-file /Users/pv-tharun/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/Session.modulevalidation -Xcc -working-directory -Xcc /Users/pv-tharun/Documents/Playgrounds/SampleListApp -enable-anonymous-context-mangled-names -file-compilation-dir /Users/pv-tharun/Documents/Playgrounds/SampleListApp -Xcc -ivfsstatcache -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator26.0-23A5260k-6c77a32d7a732e459a5b0e258bab5d26.sdkstatcache -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-generated-files.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-own-target-headers.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-all-target-headers.hmap -Xcc -iquote -Xcc /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/SampleListApp-project-headers.hmap -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources-normal/arm64 -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources/arm64 -Xcc -I/Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/DerivedSources -Xcc -DDEBUG\=1 -no-auto-bridging-header-chaining -module-name SampleListApp -frontend-parseable-output -disable-clang-spi -target-sdk-version 26.0 -target-sdk-name iphonesimulator26.0 -clang-target arm64-apple-ios26.0-simulator -o /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Build/Intermediates.noindex/SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.o -index-unit-output-path /SampleListApp.build/Debug-iphonesimulator/SampleListApp.build/Objects-normal/arm64/ViewController.o -index-store-path /Users/pv-tharun/Library/Developer/Xcode/DerivedData/SampleListApp-afdbviszwduxqdeaouvevherecak/Index.noindex/DataStore -index-system-modules
Expected behavior
The code should compile without errors or crashes, just as it does in Xcode 16
Environment
swift-driver version: 1.127.4.2 Apple Swift version 6.2 (swiftlang-6.2.0.9.909 clang-1700.3.9.907)
(Xcode 26 Beta 1 Toolchain)
Additional information
No response