$ git clone -n https://src.fedoraproject.org/rpms/gromit-mpx.git /var/lib/mock/f45-build-13039-446/root/chroot_tmpdir/scmroot/gromit-mpx
Cloning into '/var/lib/mock/f45-build-13039-446/root/chroot_tmpdir/scmroot/gromit-mpx'...
$ git fetch origin 3424ce5878e2c057c6ed2e0fa856c3b6c89d6f99:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gromit-mpx
 * [new ref]         3424ce5878e2c057c6ed2e0fa856c3b6c89d6f99 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3424ce5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild