exit status: 4, error output:
#0 0x0000000003ae91b8 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/usr/bin/swift+0x3ae91b8) #1 0x0000000003ae98f6 SignalHandler(int) (/usr/bin/swift+0x3ae98f6) #2 0x00007f1fcf2b6390 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x11390) #3 0x00000000004b0540 debugFailWithCrash() (/usr/bin/swift+0x4b0540) #4 0x00000000004aea28 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) (/usr/bin/swift+0x4aea28) #5 0x00000000004aa52b swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) (/usr/bin/swift+0x4aa52b) #6 0x0000000000465564 main (/usr/bin/swift+0x465564) #7 0x00007f1fcd9e0830 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x20830) #8 0x0000000000462e29 _start (/usr/bin/swift+0x462e29) Stack dump: 0. Program arguments: /usr/bin/swift -frontend -interpret main.swift -disable-objc-interop -debug-crash-after-parse -module-name main