$ git clone -n https://src.fedoraproject.org/rpms/plasma5support.git /var/lib/mock/f42-bootstrap-3533832-46421/root/chroot_tmpdir/scmroot/plasma5support
Cloning into '/var/lib/mock/f42-bootstrap-3533832-46421/root/chroot_tmpdir/scmroot/plasma5support'...
$ git fetch origin 5c6b0b1efce46b5333c33235f8b4e0e4849db2f6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma5support
 * [new ref]         5c6b0b1efce46b5333c33235f8b4e0e4849db2f6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5c6b0b1 6.3.5