exit status: 134 with stderr:
swift: /home/buildnode/jenkins/workspace/oss-swift-4.2-package-linux-ubuntu-16_04/swift/lib/AST/Type.cpp:3215: swift::Type swift::TypeBase::getSuperclassForDecl(const swift::ClassDecl *): Assertion `nominalDecl && "expected nominal type here"' failed. #0 0x000000000410acb4 PrintStackTraceSignalHandler(void*) (/usr/bin/swift+0x410acb4) #1 0x0000000004108b42 llvm::sys::RunSignalHandlers() (/usr/bin/swift+0x4108b42) #2 0x000000000410ae62 SignalHandler(int) (/usr/bin/swift+0x410ae62) #3 0x00007fefce714390 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x11390) #4 0x00007fefcce53428 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x35428) #5 0x00007fefcce5502a abort (/lib/x86_64-linux-gnu/libc.so.6+0x3702a) #6 0x00007fefcce4bbd7 (/lib/x86_64-linux-gnu/libc.so.6+0x2dbd7) #7 0x00007fefcce4bc82 (/lib/x86_64-linux-gnu/libc.so.6+0x2dc82) #8 0x00000000017ff77c swift::TypeBase::getSuperclassForDecl(swift::ClassDecl const*) (/usr/bin/swift+0x17ff77c) #9 0x00000000017e357a swift::ProtocolConformance::subst(swift::Type, llvm::function_ref<swift::Type (swift::SubstitutableType*)>, llvm::function_ref<llvm::Optional<swift::ProtocolConformanceRef> (swift::CanType, swift::Type, swift::ProtocolType*)>) const (/usr/bin/swift+0x17e357a) #10 0x00000000013c9607 swift::ConformanceChecker::ensureRequirementsAreSatisfied(bool)::GatherConformancesListener::satisfiedConformance(swift::Type, swift::Type, swift::ProtocolConformanceRef) (/usr/bin/swift+0x13c9607) #11 0x00000000013a7582 swift::TypeChecker::checkGenericArguments(swift::DeclContext*, swift::SourceLoc, swift::SourceLoc, swift::Type, swift::ArrayRefView<swift::Type, swift::GenericTypeParamType*, swift::GenericTypeParamType* swift::staticCastHelper<swift::GenericTypeParamType>(swift::Type const&), true>, llvm::ArrayRef<swift::Requirement>, llvm::function_ref<swift::Type (swift::SubstitutableType*)>, llvm::function_ref<llvm::Optional<swift::ProtocolConformanceRef> (swift::CanType, swift::Type, swift::Prot