$ git clone -n https://src.fedoraproject.org/rpms/postgis.git /var/lib/mock/f42-build-862965-171273/root/chroot_tmpdir/scmroot/postgis
Cloning into '/var/lib/mock/f42-build-862965-171273/root/chroot_tmpdir/scmroot/postgis'...
$ git fetch origin 758524acc32c7b62ca757bd0c55b971299fc64fb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/postgis
 * [new ref]         758524acc32c7b62ca757bd0c55b971299fc64fb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 758524a Rebuild (GDAL)