I’ll try the same at home, under Linux. Depending on the outcome, the starting point for investigating this behaviour would probably be different (OS-specific or not).
Edit: Tried it. compile_incremental works fine, but build_executable fails with
/home/linuxbrew/.linuxbrew/bin/ld: //home/asprionj/Documents/PortableSW/julia-1.1.0/lib/julia/libLLVM-6.0.so: undefined reference to `std::thread::_State::~_State()@GLIBCXX_3.4.22'
/home/linuxbrew/.linuxbrew/bin/ld: //home/asprionj/Documents/PortableSW/julia-1.1.0/lib/julia/libLLVM-6.0.so: undefined reference to `std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)())@GLIBCXX_3.4.22'
collect2: error: ld returned 1 exit status
So, cannot compare it right now.