$ git clone -n https://src.fedoraproject.org/rpms/plasma-mobile.git /var/lib/mock/f42-build-side-1-3585196-46903/root/chroot_tmpdir/scmroot/plasma-mobile
Cloning into '/var/lib/mock/f42-build-side-1-3585196-46903/root/chroot_tmpdir/scmroot/plasma-mobile'...
$ git fetch origin 3e329d06de1f5fda7bccfdd367f3877b30eaf1b9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-mobile
 * [new ref]         3e329d06de1f5fda7bccfdd367f3877b30eaf1b9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3e329d0 6.4.2