$ git clone -n https://src.fedoraproject.org/rpms/golang-modernc-golex.git /var/lib/mock/f45-build-12686-443/root/chroot_tmpdir/scmroot/golang-modernc-golex
Cloning into '/var/lib/mock/f45-build-12686-443/root/chroot_tmpdir/scmroot/golang-modernc-golex'...
$ git fetch origin f70d5c989912b389395560a0f3bb0d7148a7d3e1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-modernc-golex
 * [new ref]         f70d5c989912b389395560a0f3bb0d7148a7d3e1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f70d5c9 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild