$ git clone -n https://src.fedoraproject.org/rpms/gummi.git /var/lib/mock/f45-build-13254-448/root/chroot_tmpdir/scmroot/gummi
Cloning into '/var/lib/mock/f45-build-13254-448/root/chroot_tmpdir/scmroot/gummi'...
$ git fetch origin d0ccc7331fc7ededd792fc6843113d9a124bcb34:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gummi
 * [new ref]         d0ccc7331fc7ededd792fc6843113d9a124bcb34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d0ccc73 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild