$ git clone -n https://src.fedoraproject.org/rpms/plasma-pa.git /var/lib/mock/f42-build-side-1-3578410-46814/root/chroot_tmpdir/scmroot/plasma-pa
Cloning into '/var/lib/mock/f42-build-side-1-3578410-46814/root/chroot_tmpdir/scmroot/plasma-pa'...
$ git fetch origin c808b515e15927a224ea3ff23aae09cc101461c0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-pa
 * [new ref]         c808b515e15927a224ea3ff23aae09cc101461c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c808b51 6.4.1