$ git clone -n https://src.fedoraproject.org/rpms/blake3.git /var/lib/mock/f40-build-793166-138796/root/chroot_tmpdir/scmroot/blake3
Cloning into '/var/lib/mock/f40-build-793166-138796/root/chroot_tmpdir/scmroot/blake3'...
$ git fetch origin 2cbd8c9595fec530de086172839acfd707e6b2d3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/blake3
 * [new ref]         2cbd8c9595fec530de086172839acfd707e6b2d3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2cbd8c9 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild