$ git clone -n https://src.fedoraproject.org/rpms/swig.git /var/lib/mock/f42-bootstrap-3462953-45593/root/chroot_tmpdir/scmroot/swig
Cloning into '/var/lib/mock/f42-bootstrap-3462953-45593/root/chroot_tmpdir/scmroot/swig'...
$ git fetch origin 6d8e3c92689366e220c66320ea499cdd93be05ed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/swig
 * [new ref]         6d8e3c92689366e220c66320ea499cdd93be05ed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6d8e3c9 Disable R tests, because they need tcl < 9