> `clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]` That's the crux of your failure. You're compiling C code as C++, which isn't going to work. You should use `clang` instead of `clang++` Also, you probably want to bring in `shell.c` if you want to build an executable.