The `-v` flag means verbose and not version. With `clang` this flag prints the version and exits successfully. Under `GCC` this is not a valid command line so the binary exits with an error.
LLVM libc ========= This directory and its subdirectories contain source code for llvm-libc, a retargetable implementation of the C standard library. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.