Mutating subscript on variadic generic type #84037
Description
Description
defining a settable subscript on a type that contains parameter pack crashes the compiler
Reproduction
struct GenericPack<each T> {
var values: (repeat each T)
subscript() -> (repeat each T) {
get { (repeat each values) }
set {} // only builds by removing this line
}
}Stack dump
0. Program arguments: /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c -primary-file /Users/lteveli/github/tevelee/test/test/test.swift -emit-dependencies-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.d -emit-const-values-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.swiftconstvalues -emit-reference-dependencies-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.swiftdeps -serialize-diagnostics-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.dia -emit-localized-strings -emit-localized-strings-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64 -target arm64-apple-ios26.0-simulator -load-resolved-plugin /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftMacros.dylib#/Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server#SwiftMacros -disable-implicit-swift-modules -Xcc -fno-implicit-modules -Xcc -fno-implicit-module-maps -explicit-swift-module-map-file /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test-dependencies-8.json -Xllvm -aarch64-use-tbi -enable-objc-interop -sdk /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk -I /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator -F /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator -no-color-diagnostics -Xcc -fno-color-diagnostics -enable-library-evolution -enable-testing -g -debug-info-format=dwarf -dwarf-version=5 -module-cache-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/SwiftExplicitPrecompiledModules -swift-version 5 -enforce-exclusivity=checked -Onone -D DEBUG -serialize-debugging-options -const-gather-protocols-file /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test_const_extract_protocols.json -enable-upcoming-feature DisableOutwardActorInference -enable-upcoming-feature InferSendableFromCaptures -enable-upcoming-feature GlobalActorIsolatedTypesUsability -enable-upcoming-feature MemberImportVisibility -enable-upcoming-feature InferIsolatedConformances -enable-upcoming-feature NonisolatedNonsendingByDefault -enable-experimental-feature DebugDescriptionMacro -enable-bare-slash-regex -validate-clang-modules-once -clang-build-session-file /Users/lteveli/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/Session.modulevalidation -Xcc -working-directory -Xcc /Users/lteveli/github/tevelee/test -enable-anonymous-context-mangled-names -file-compilation-dir /Users/lteveli/github/tevelee/test -Xcc -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG -Xcc -ivfsstatcache -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator26.0-23A5324a-3c07539e1689a2e00432bfef618aaefb.sdkstatcache -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-generated-files.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-own-target-headers.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-all-target-headers.hmap -Xcc -iquote -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-project-headers.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources-normal/arm64 -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources/arm64 -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources -Xcc -DDEBUG=1 -no-auto-bridging-header-chaining -module-name test -frontend-parseable-output -disable-clang-spi -target-sdk-version 26.0 -target-sdk-name iphonesimulator26.0 -clang-target arm64-apple-ios26.0-simulator -in-process-plugin-server-path /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -parse-as-library -o /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.o -index-unit-output-path /test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.o -index-store-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Index.noindex/DataStore -index-system-modules
1. Apple Swift version 6.2 (swiftlang-6.2.0.19.9 clang-1700.3.19.1)
2. Compiling with effective version 5.10
3. While evaluating request ASTLoweringRequest(Lowering AST to SIL for file "/Users/lteveli/github/tevelee/test/test/test.swift")
4. While silgen emitFunction SIL function "@$s4test11GenericPackVxxQp_tyciM".
for modify for subscript() (at /Users/lteveli/github/tevelee/test/test/test.swift:4:5)
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 0x00000001074fdbcc llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1 swift-frontend 0x00000001074fb55c llvm::sys::RunSignalHandlers() + 112
2 swift-frontend 0x00000001074fe1f8 SignalHandler(int, __siginfo*, void*) + 344
3 libsystem_platform.dylib 0x000000018f8ad6a4 _sigtramp + 56
4 swift-frontend 0x0000000101a899fc swift::OpenPackElementInst::create(swift::SILFunction&, swift::SILDebugLocation, swift::SILValue, swift::GenericEnvironment*) + 120
5 swift-frontend 0x0000000101a899fc swift::OpenPackElementInst::create(swift::SILFunction&, swift::SILDebugLocation, swift::SILValue, swift::GenericEnvironment*) + 120
6 swift-frontend 0x0000000101d2e88c swift::Lowering::SILGenFunction::emitDynamicPackLoop(swift::SILLocation, swift::CanTypeWrapper<swift::PackType>, unsigned int, swift::SILValue, swift::SILValue, swift::GenericEnvironment*, bool, llvm::function_ref<void (swift::SILValue, swift::SILValue, swift::SILValue)>, swift::SILBasicBlock*) + 1708
7 swift-frontend 0x0000000101c535f4 (anonymous namespace)::ArgEmitter::emitPackArg(llvm::MutableArrayRef<swift::Lowering::ArgumentSource>, swift::Lowering::AbstractionPattern) + 3532
8 swift-frontend 0x0000000101c52758 void llvm::function_ref<void (swift::Lowering::TupleElementGenerator&)>::callback_fn<(anonymous namespace)::ArgEmitter::emitExpanded(swift::Lowering::ArgumentSource&&, swift::Lowering::AbstractionPattern)::'lambda'(swift::Lowering::TupleElementGenerator&)>(long, swift::Lowering::TupleElementGenerator&) + 356
9 swift-frontend 0x0000000101a051fc swift::Lowering::AbstractionPattern::forEachTupleElement(swift::CanType, llvm::function_ref<void (swift::Lowering::TupleElementGenerator&)>) const + 184
10 swift-frontend 0x0000000101c51318 (anonymous namespace)::ArgEmitter::emit(swift::Lowering::ArgumentSource&&, swift::Lowering::AbstractionPattern, bool, std::__1::optional<swift::AnyFunctionType::Param>) + 3688
11 swift-frontend 0x0000000101c3e4e0 (anonymous namespace)::ArgEmitter::emitSingleArg(swift::Lowering::ArgumentSource&&, swift::Lowering::AbstractionPattern, bool, std::__1::optional<swift::AnyFunctionType::Param>) + 204
12 swift-frontend 0x0000000101c4faf0 (anonymous namespace)::ArgEmitter::emitPreparedArgs(swift::Lowering::PreparedArguments&&, swift::Lowering::AbstractionPattern, llvm::ArrayRef<swift::LifetimeDependenceInfo>) + 304
13 swift-frontend 0x0000000101c5ca20 (anonymous namespace)::CallSite::emit(swift::Lowering::SILGenFunction&, swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::SILFunctionType>, llvm::ArrayRef<swift::LifetimeDependenceInfo>, (anonymous namespace)::ParamLowering&, llvm::SmallVectorImpl<swift::Lowering::ManagedValue>&, llvm::SmallVectorImpl<(anonymous namespace)::DelayedArgument>&, swift::ForeignInfo const&) && + 676
14 swift-frontend 0x0000000101c5c1d8 (anonymous namespace)::CallEmission::emitArgumentsForNormalApply(swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::SILFunctionType>, llvm::ArrayRef<swift::LifetimeDependenceInfo>, swift::ForeignInfo const&, llvm::SmallVectorImpl<swift::Lowering::ManagedValue>&, std::__1::optional<swift::SILLocation>&) + 1112
15 swift-frontend 0x0000000101c43100 (anonymous namespace)::CallEmission::apply(swift::Lowering::SGFContext) + 1092
16 swift-frontend 0x0000000101c4b0f0 swift::Lowering::SILGenFunction::emitSetAccessor(swift::SILLocation, swift::SILDeclRef, swift::SubstitutionMap, swift::Lowering::ArgumentSource&&, bool, bool, swift::Lowering::PreparedArguments&&, swift::Lowering::ArgumentSource&&, bool) + 1324
17 swift-frontend 0x0000000101d20330 swift::Lowering::SILGenFunction::emitAssignToLValue(swift::SILLocation, swift::Lowering::ArgumentSource&&, swift::Lowering::LValue&&) + 1948
18 swift-frontend 0x0000000101d28bcc (anonymous namespace)::MaterializeToTemporaryComponent::set(swift::Lowering::SILGenFunction&, swift::SILLocation, swift::Lowering::ArgumentSource&&, swift::Lowering::ManagedValue) && + 96
19 swift-frontend 0x0000000101d12558 swift::Lowering::LogicalPathComponent::writeback(swift::Lowering::SILGenFunction&, swift::SILLocation, swift::Lowering::ManagedValue, swift::Lowering::MaterializedLValue, bool) + 628
20 swift-frontend 0x0000000101d20be4 (anonymous namespace)::LValueWritebackCleanup::emit(swift::Lowering::SILGenFunction&, swift::CleanupLocation, swift::Lowering::ForUnwind_t) + 148
21 swift-frontend 0x0000000101c0f9f0 swift::Lowering::CleanupManager::emitCleanups(swift::DiverseStackBase::stable_iterator, swift::CleanupLocation, swift::Lowering::ForUnwind_t, bool) + 340
22 swift-frontend 0x0000000101c3f7ec swift::Lowering::SILGenFunction::emitRawYield(swift::SILLocation, llvm::ArrayRef<swift::Lowering::ManagedValue>, swift::Lowering::JumpDest, bool) + 932
23 swift-frontend 0x0000000101c3e31c swift::Lowering::SILGenFunction::emitYield(swift::SILLocation, llvm::MutableArrayRef<swift::Lowering::ArgumentSource>, llvm::ArrayRef<swift::Lowering::AbstractionPattern>, swift::Lowering::JumpDest) + 1080
24 swift-frontend 0x0000000101d7751c swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 5544
25 swift-frontend 0x0000000101d777cc swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 6232
26 swift-frontend 0x0000000101cef5ac swift::Lowering::SILGenFunction::emitFunction(swift::FuncDecl*) + 384
27 swift-frontend 0x0000000101c2a6ac swift::Lowering::SILGenModule::emitFunctionDefinition(swift::SILDeclRef, swift::SILFunction*) + 7596
28 swift-frontend 0x0000000101c2b6f0 swift::Lowering::SILGenModule::emitOrDelayFunction(swift::SILDeclRef) + 236
29 swift-frontend 0x0000000101c288ec swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 136
30 swift-frontend 0x0000000101d92668 (anonymous namespace)::SILGenType::visitFuncDecl(swift::FuncDecl*) + 32
31 swift-frontend 0x0000000102b0c9f0 void llvm::function_ref<void (swift::AccessorKind)>::callback_fn<swift::AbstractStorageDecl::visitOpaqueAccessors(llvm::function_ref<void (swift::AccessorDecl*)>) const::$_0>(long, swift::AccessorKind) + 204
32 swift-frontend 0x0000000102ac50e8 swift::AbstractStorageDecl::visitExpectedOpaqueAccessors(llvm::function_ref<void (swift::AccessorKind)>) const + 264
33 swift-frontend 0x0000000101d928a0 (anonymous namespace)::SILGenType::visitAbstractStorageDecl(swift::AbstractStorageDecl*) + 304
34 swift-frontend 0x0000000101d8e48c (anonymous namespace)::SILGenType::emitType() + 488
35 swift-frontend 0x0000000101c28600 swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visit(swift::Decl*) + 100
36 swift-frontend 0x0000000101c2f538 swift::ASTLoweringRequest::evaluate(swift::Evaluator&, swift::ASTLoweringDescriptor) const + 2364
37 swift-frontend 0x0000000101d7561c swift::SimpleRequest<swift::ASTLoweringRequest, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>> (swift::ASTLoweringDescriptor), (swift::RequestFlags)17>::evaluateRequest(swift::ASTLoweringRequest const&, swift::Evaluator&) + 208
38 swift-frontend 0x0000000101c33fc0 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'()) + 572
39 swift-frontend 0x0000000101137708 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 964
40 swift-frontend 0x000000010113aa7c performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1764
41 swift-frontend 0x000000010113968c swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3580
42 swift-frontend 0x00000001010bac6c swift::mainEntry(int, char const**) + 5412
43 dyld 0x000000018f4d2b98 start + 6076
Failed frontend command:
/Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c -primary-file /Users/lteveli/github/tevelee/test/test/test.swift -emit-dependencies-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.d -emit-const-values-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.swiftconstvalues -emit-reference-dependencies-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.swiftdeps -serialize-diagnostics-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.dia -emit-localized-strings -emit-localized-strings-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64 -target arm64-apple-ios26.0-simulator -load-resolved-plugin /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib/swift/host/plugins/libSwiftMacros.dylib\#/Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/swift-plugin-server\#SwiftMacros -disable-implicit-swift-modules -Xcc -fno-implicit-modules -Xcc -fno-implicit-module-maps -explicit-swift-module-map-file /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test-dependencies-8.json -Xllvm -aarch64-use-tbi -enable-objc-interop -sdk /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator26.0.sdk -I /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator -F /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator -no-color-diagnostics -Xcc -fno-color-diagnostics -enable-library-evolution -enable-testing -g -debug-info-format\=dwarf -dwarf-version\=5 -module-cache-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/SwiftExplicitPrecompiledModules -swift-version 5 -enforce-exclusivity\=checked -Onone -D DEBUG -serialize-debugging-options -const-gather-protocols-file /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test_const_extract_protocols.json -enable-upcoming-feature DisableOutwardActorInference -enable-upcoming-feature InferSendableFromCaptures -enable-upcoming-feature GlobalActorIsolatedTypesUsability -enable-upcoming-feature MemberImportVisibility -enable-upcoming-feature InferIsolatedConformances -enable-upcoming-feature NonisolatedNonsendingByDefault -enable-experimental-feature DebugDescriptionMacro -enable-bare-slash-regex -validate-clang-modules-once -clang-build-session-file /Users/lteveli/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/Session.modulevalidation -Xcc -working-directory -Xcc /Users/lteveli/github/tevelee/test -enable-anonymous-context-mangled-names -file-compilation-dir /Users/lteveli/github/tevelee/test -Xcc -D_LIBCPP_HARDENING_MODE\=_LIBCPP_HARDENING_MODE_DEBUG -Xcc -ivfsstatcache -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator26.0-23A5324a-3c07539e1689a2e00432bfef618aaefb.sdkstatcache -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-generated-files.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-own-target-headers.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-all-target-headers.hmap -Xcc -iquote -Xcc /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/test-project-headers.hmap -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources-normal/arm64 -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources/arm64 -Xcc -I/Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/DerivedSources -Xcc -DDEBUG\=1 -no-auto-bridging-header-chaining -module-name test -frontend-parseable-output -disable-clang-spi -target-sdk-version 26.0 -target-sdk-name iphonesimulator26.0 -clang-target arm64-apple-ios26.0-simulator -in-process-plugin-server-path /Applications/Xcode-26.0.0-Beta.6.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -parse-as-library -o /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Build/Intermediates.noindex/test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.o -index-unit-output-path /test.build/Debug-iphonesimulator/test.build/Objects-normal/arm64/test.o -index-store-path /Users/lteveli/Library/Developer/Xcode/DerivedData/test-farpwibvptjdisecoxenrhlutlzq/Index.noindex/DataStore -index-system-modules
Expected behavior
I did expect this to compile, or throw a compilation error if mutating subscripts are not (yet) supported
Environment
swift-driver version: 1.127.14.1 Apple Swift version 6.2 (swiftlang-6.2.0.19.9 clang-1700.3.19.1)
Target: arm64-apple-macosx15.0
Additional information
No response