$ git clone -n https://src.fedoraproject.org/rpms/mesa.git /var/lib/mock/f39-build-2092087-50235/root/chroot_tmpdir/scmroot/mesa
Cloning into '/var/lib/mock/f39-build-2092087-50235/root/chroot_tmpdir/scmroot/mesa'...
$ git fetch origin 49240cd70e9c1be161f7294c82a93fe1f66e2961:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mesa
 * [new ref]         49240cd70e9c1be161f7294c82a93fe1f66e2961 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 49240cd Fix gtk4-demo regression on older Intel