$ git clone -n https://src.fedoraproject.org/rpms/spacer.git /var/lib/mock/f45-build-46424-834/root/chroot_tmpdir/scmroot/spacer
Cloning into '/var/lib/mock/f45-build-46424-834/root/chroot_tmpdir/scmroot/spacer'...
$ git fetch origin 10683357291dd7b5bd77a1d56fbb7e85e6cb2186:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/spacer
 * [new ref]         10683357291dd7b5bd77a1d56fbb7e85e6cb2186 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1068335 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild