$ git clone -n https://src.fedoraproject.org/rpms/spacebar.git /var/lib/mock/f42-build-881098-183116/root/chroot_tmpdir/scmroot/spacebar
Cloning into '/var/lib/mock/f42-build-881098-183116/root/chroot_tmpdir/scmroot/spacebar'...
$ git fetch origin 8bfe0757679841551c5764a425c8f071eead2b8b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/spacebar
 * [new ref]         8bfe0757679841551c5764a425c8f071eead2b8b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8bfe075 6.3.2