All programs, in particular also the stand-alone programs (non-builtins)
must call git_extract_argv0_path(argv[0]) in order to help builds that
derive the installation prefix at runtime, such as the MinGW build.
Without this call, the program segfaults (or raises an assertion
failure).
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Tested-by: Michael Wookey <michaelwookey@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>