Package Julia fails to build in rawhide since gcc 5.0.0-0.12.fc23 has been uploaded to the repos. I'm building nightlies in Copr at https://copr.fedoraproject.org/coprs/nalimilan/julia-nightlies/, and suddenly the build started to fail only on rawhide. So I've tested rebuilding the existing version, and it fails too. I'm not sure the problem is gcc, but it looks like a good candidate.

Note Julia was not listed in the failing packages in your message to fedora-devel: https://lists.fedoraproject.org/pipermail/devel/2015-February/207549.html

The error is:
g++ -march=x86-64 -m64 -O3 -ggdb3 -falign-functions -momit-leaf-frame-pointer -I/builddir/build/BUILD/julia-0.3.5/src -I/builddir/build/BUILD/julia-0.3.5/src/support -I/builddir/build/BUILD/julia-0.3.5/build/usr/include -Wall -Wno-strict-aliasing -fno-omit-frame-pointer repl.o -o /builddir/build/BUILD/julia-0.3.5/build/usr/bin/julia -L/builddir/build/BUILD/julia-0.3.5/build/usr/lib64/julia -L/builddir/build/BUILD/julia-0.3.5/build/usr/lib64 -L/builddir/build/BUILD/julia-0.3.5/build/usr/lib64 -ljulia -Wl,-Bdynamic -Wl,--no-whole-archive -ldl -lrt -lpthread -Wl,--export-dynamic -Wl,--version-script=/builddir/build/BUILD/julia-0.3.5/src/julia.expmap -Wl,--no-whole-archive -lunwind-generic -lunwind -L/usr/lib64/llvm -lLLVM-3.5.0 -Wl,-rpath,$ORIGIN/../lib64/julia -Wl,-rpath,$ORIGIN/../lib64 -Wl,-z,origin
/builddir/build/BUILD/julia-0.3.5/build/usr/lib64/libjulia.so: undefined reference to `llvm::TargetRegistry::lookupTarget(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)'
/builddir/build/BUILD/julia-0.3.5/build/usr/lib64/libjulia.so: undefined reference to `llvm::LoopPass::createPrinterPass(llvm::raw_ostream&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const'
/builddir/build/BUILD/julia-0.3.5/build/usr/lib64/libjulia.so: undefined reference to `llvm::EngineBuilder::selectTarget(llvm::Triple const&, llvm::StringRef, llvm::StringRef, llvm::SmallVectorImpl<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&)'
/builddir/build/BUILD/julia-0.3.5/build/usr/lib64/libjulia.so: undefined reference to `llvm::raw_fd_ostream::raw_fd_ostream(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, llvm::sys::fs::OpenFlags)'
collect2: error: ld returned 1 exit status

See this Koji build for details:
http://koji.fedoraproject.org/koji/taskinfo?taskID=8948758