$ git clone -n https://src.fedoraproject.org/rpms/erlang-fast_yaml.git /var/lib/mock/f40-build-1777636-24803/root/chroot_tmpdir/scmroot/erlang-fast_yaml
Cloning into '/var/lib/mock/f40-build-1777636-24803/root/chroot_tmpdir/scmroot/erlang-fast_yaml'...
$ git fetch origin 1ab721744f86a9893dd56e88c5f7ed2e822730f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/erlang-fast_yaml
 * [new ref]         1ab721744f86a9893dd56e88c5f7ed2e822730f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1ab7217 fast_yaml ver. 1.0.37