$ git clone -n https://src.fedoraproject.org/rpms/spherical-cow-backgrounds.git /var/lib/mock/f40-build-2170833-51033/root/chroot_tmpdir/scmroot/spherical-cow-backgrounds
Cloning into '/var/lib/mock/f40-build-2170833-51033/root/chroot_tmpdir/scmroot/spherical-cow-backgrounds'...
$ git fetch origin 40a3a2e5c6de27b36815d9628b93d46efe319efb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/spherical-cow-backgrounds
 * [new ref]         40a3a2e5c6de27b36815d9628b93d46efe319efb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 40a3a2e Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild