$ git clone -n https://src.fedoraproject.org/rpms/libmatchbox.git /var/lib/mock/f45-build-16513-487/root/chroot_tmpdir/scmroot/libmatchbox
Cloning into '/var/lib/mock/f45-build-16513-487/root/chroot_tmpdir/scmroot/libmatchbox'...
$ git fetch origin 8150003e5b008bc8f8146a67dcd676f384890145:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libmatchbox
 * [new ref]         8150003e5b008bc8f8146a67dcd676f384890145 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8150003 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild