$ git clone -n https://src.fedoraproject.org/rpms/gnubik.git /var/lib/mock/f41-build-858015-168289/root/chroot_tmpdir/scmroot/gnubik
Cloning into '/var/lib/mock/f41-build-858015-168289/root/chroot_tmpdir/scmroot/gnubik'...
$ git fetch origin ff2ac19bd3aa4403d8d70c83f1e016128e899c12:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnubik
 * [new ref]         ff2ac19bd3aa4403d8d70c83f1e016128e899c12 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff2ac19 Build with guile 3.0