$ git clone -n https://src.fedoraproject.org/rpms/perl-Sort-MergeSort.git /var/lib/mock/f45-build-26246-616/root/chroot_tmpdir/scmroot/perl-Sort-MergeSort
Cloning into '/var/lib/mock/f45-build-26246-616/root/chroot_tmpdir/scmroot/perl-Sort-MergeSort'...
$ git fetch origin ae5c54a23c5f4b6ded6db9500c860227302618b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Sort-MergeSort
 * [new ref]         ae5c54a23c5f4b6ded6db9500c860227302618b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ae5c54a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild