$ git clone -n https://src.fedoraproject.org/rpms/buildstream.git /var/lib/mock/f40-build-2271661-54891/root/chroot_tmpdir/scmroot/buildstream
Cloning into '/var/lib/mock/f40-build-2271661-54891/root/chroot_tmpdir/scmroot/buildstream'...
$ git fetch origin bf5adf7b2e786f6bd7ff4e8eaaa3a96ec06da9d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/buildstream
 * [new ref]         bf5adf7b2e786f6bd7ff4e8eaaa3a96ec06da9d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf5adf7 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild