$ git clone -n https://src.fedoraproject.org/rpms/golang-modernc-mathutil.git /var/lib/mock/f45-build-12720-443/root/chroot_tmpdir/scmroot/golang-modernc-mathutil
Cloning into '/var/lib/mock/f45-build-12720-443/root/chroot_tmpdir/scmroot/golang-modernc-mathutil'...
$ git fetch origin c50ed77760bef58ac3292ef9b0a1499a8e73b314:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-modernc-mathutil
 * [new ref]         c50ed77760bef58ac3292ef9b0a1499a8e73b314 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c50ed77 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild