$ git clone -n https://src.fedoraproject.org/rpms/plasma-workspace.git /var/lib/mock/f42-bootstrap-3533708-46421/root/chroot_tmpdir/scmroot/plasma-workspace
Cloning into '/var/lib/mock/f42-bootstrap-3533708-46421/root/chroot_tmpdir/scmroot/plasma-workspace'...
$ git fetch origin 2e657ea062df260e2c9373f5680645c47602a2d3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-workspace
 * [new ref]         2e657ea062df260e2c9373f5680645c47602a2d3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e657ea 6.3.5