$ git clone -n https://src.fedoraproject.org/rpms/mock.git /var/lib/mock/f40-build-2298409-56520/root/chroot_tmpdir/scmroot/mock
Cloning into '/var/lib/mock/f40-build-2298409-56520/root/chroot_tmpdir/scmroot/mock'...
$ git fetch origin 81d0e63b83a0d8ac686c348421dc5a5e5da1bf10:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mock
 * [new ref]         81d0e63b83a0d8ac686c348421dc5a5e5da1bf10 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 81d0e63 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild