$ git clone -n https://src.fedoraproject.org/rpms/kf5-kdesu.git /var/lib/mock/f40-build-786954-134636/root/chroot_tmpdir/scmroot/kf5-kdesu
Cloning into '/var/lib/mock/f40-build-786954-134636/root/chroot_tmpdir/scmroot/kf5-kdesu'...
$ git fetch origin f339c37b2a52632988da18e4f327562a766dc41a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf5-kdesu
 * [new ref]         f339c37b2a52632988da18e4f327562a766dc41a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f339c37 5.115.0