$ git clone -n https://src.fedoraproject.org/rpms/mathicgb.git /var/lib/mock/f40-build-2265264-54596/root/chroot_tmpdir/scmroot/mathicgb
Cloning into '/var/lib/mock/f40-build-2265264-54596/root/chroot_tmpdir/scmroot/mathicgb'...
$ git fetch origin 693df604ec18700dae50e118a6ef25714ad7efd3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mathicgb
 * [new ref]         693df604ec18700dae50e118a6ef25714ad7efd3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 693df60 Rebuilt for TBB 2021.11