$ git clone -n https://src.fedoraproject.org/forks/u2fsdgvkx1/rpms/filesystem.git /var/lib/mock/f42-build-3496583-45906/root/chroot_tmpdir/scmroot/filesystem
Cloning into '/var/lib/mock/f42-build-3496583-45906/root/chroot_tmpdir/scmroot/filesystem'...
$ git fetch origin dea1713299fdb9587fca0cb444d42daaa4b5c8a8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/u2fsdgvkx1/rpms/filesystem
 * [new ref]         dea1713299fdb9587fca0cb444d42daaa4b5c8a8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dea1713 Add lp64d symlink to parent directory on riscv64