$ git clone -n https://src.fedoraproject.org/rpms/MUMPS.git /var/lib/mock/f45-build-1084-296/root/chroot_tmpdir/scmroot/MUMPS
Cloning into '/var/lib/mock/f45-build-1084-296/root/chroot_tmpdir/scmroot/MUMPS'...
$ git fetch origin a84c457eec5b4b23389adba457c056f6a16f152c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/MUMPS
 * [new ref]         a84c457eec5b4b23389adba457c056f6a16f152c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a84c457 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild