$ git clone -n https://src.fedoraproject.org/rpms/plasma-disks.git /var/lib/mock/f42-build-side-1-3566297-46733/root/chroot_tmpdir/scmroot/plasma-disks
Cloning into '/var/lib/mock/f42-build-side-1-3566297-46733/root/chroot_tmpdir/scmroot/plasma-disks'...
$ git fetch origin 6ba13df6f39aa9a0744a96eab6fd65768e8c8fef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-disks
 * [new ref]         6ba13df6f39aa9a0744a96eab6fd65768e8c8fef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6ba13df 6.4.0