$ git clone -n https://src.fedoraproject.org/rpms/spacebar.git /var/lib/mock/f42-build-side-1-3573387-46767/root/chroot_tmpdir/scmroot/spacebar
Cloning into '/var/lib/mock/f42-build-side-1-3573387-46767/root/chroot_tmpdir/scmroot/spacebar'...
$ git fetch origin 87db19354bd18c40b7ce3c515ba1ad290aee0bd9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/spacebar
 * [new ref]         87db19354bd18c40b7ce3c515ba1ad290aee0bd9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 87db193 6.4.0