$ git clone -n https://src.fedoraproject.org/rpms/mediawiki.git /var/lib/mock/f42-build-3273841-41312/root/chroot_tmpdir/scmroot/mediawiki
Cloning into '/var/lib/mock/f42-build-3273841-41312/root/chroot_tmpdir/scmroot/mediawiki'...
$ git fetch origin d6fb66067514f648d5c604d898c39abf7facd2f5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mediawiki
 * [new ref]         d6fb66067514f648d5c604d898c39abf7facd2f5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d6fb660 Update autoload paths