$ git clone -n https://src.fedoraproject.org/rpms/kscreen.git /var/lib/mock/f42-bootstrap-3533978-46428/root/chroot_tmpdir/scmroot/kscreen
Cloning into '/var/lib/mock/f42-bootstrap-3533978-46428/root/chroot_tmpdir/scmroot/kscreen'...
$ git fetch origin 5fbcf2691f8e6bbc40acd0a26fc85d85e8413638:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kscreen
 * [new ref]         5fbcf2691f8e6bbc40acd0a26fc85d85e8413638 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5fbcf26 6.3.5