$ git clone -n https://src.fedoraproject.org/rpms/mapnik.git /var/lib/mock/f40-build-1723634-24647/root/chroot_tmpdir/scmroot/mapnik
Cloning into '/var/lib/mock/f40-build-1723634-24647/root/chroot_tmpdir/scmroot/mapnik'...
$ git fetch origin ffc3691d51088714156c9bf974f72b1c480e38b1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mapnik
 * [new ref]         ffc3691d51088714156c9bf974f72b1c480e38b1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ffc3691 Rebuild for ICU 74