$ git clone -n https://src.fedoraproject.org/rpms/blake3.git /var/lib/mock/f40-build-1314979-23514/root/chroot_tmpdir/scmroot/blake3
Cloning into '/var/lib/mock/f40-build-1314979-23514/root/chroot_tmpdir/scmroot/blake3'...
$ git fetch origin 3cbb440c9b46636f55ebec758e2e791dbf7f64a1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/blake3
 * [new ref]         3cbb440c9b46636f55ebec758e2e791dbf7f64a1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3cbb440 Use %autorelease and remove non-%autochangelog entries