$ git clone -n https://src.fedoraproject.org/rpms/postgis.git /var/lib/mock/f40-build-1844932-24973/root/chroot_tmpdir/scmroot/postgis
Cloning into '/var/lib/mock/f40-build-1844932-24973/root/chroot_tmpdir/scmroot/postgis'...
$ git fetch origin 16f765594c879a7135a1a293eb1fbff0830eaec8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/postgis
 * [new ref]         16f765594c879a7135a1a293eb1fbff0830eaec8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 16f7655 Update to 3.4.2