$ git clone -n https://src.fedoraproject.org/rpms/plasma-oxygen.git /var/lib/mock/f40-build-2244284-53701/root/chroot_tmpdir/scmroot/plasma-oxygen
Cloning into '/var/lib/mock/f40-build-2244284-53701/root/chroot_tmpdir/scmroot/plasma-oxygen'...
$ git fetch origin 70c431cf68a3c03670e408015164a7057ae36854:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-oxygen
 * [new ref]         70c431cf68a3c03670e408015164a7057ae36854 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70c431c 5.92.0