This is the derivation I use when running `nix store diff-closures` for the
weekly nixpkgs update.

The derivation also includes some attributes that are useful for exploring the
various grid configurations in the nix repl.

now that default.nix is actually somewhat useful

`cp --recursive ...` is required for permission issues
`... --out-link result-docs` is required for path collision issues
the rest is at my discretion