$ git clone -n https://src.fedoraproject.org/rpms/goverlay.git /var/lib/mock/f40-build-2704422-70940/root/chroot_tmpdir/scmroot/goverlay
Cloning into '/var/lib/mock/f40-build-2704422-70940/root/chroot_tmpdir/scmroot/goverlay'...
$ git fetch origin a591dfd94514aaefe129be9ff48d66474dbeebbf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/goverlay
 * [new ref]         a591dfd94514aaefe129be9ff48d66474dbeebbf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a591dfd build: Update to 1.1.1