$ git clone -n https://src.fedoraproject.org/rpms/module-build-service.git /var/lib/mock/f41-build-side-1-3129806-39586/root/chroot_tmpdir/scmroot/module-build-service
Cloning into '/var/lib/mock/f41-build-side-1-3129806-39586/root/chroot_tmpdir/scmroot/module-build-service'...
$ git fetch origin 920f1845d372ffa78b3b0ef93bc9a26821ace667:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/module-build-service
 * [new ref]         920f1845d372ffa78b3b0ef93bc9a26821ace667 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 920f184 Retired, see https://bugzilla.redhat.com/2291560