ssh-pull.con commit show-ref --hash=len, --abbrev=len, and --abbrev (2eaf222)
   1#define COUNTERPART_ENV_NAME "GIT_SSH_PUSH"
   2#define COUNTERPART_PROGRAM_NAME "git-ssh-push"
   3#define MY_PROGRAM_NAME "git-ssh-pull"
   4#include "ssh-fetch.c"