Is there a `nix-shell` equivalent to the `-f ...` in `nix-env -f /path/to/nixpkgs -iA attrname`? I want to test my modified `taglib` derivation in IPython, so I tried ``` nix-shell -p 'python36.withPackages(ps: with ps; [ ps.ipython ps.tablib ])' ~/dev/nixos/nixpkgs/ ``` but that resulted in `error: syntax error, unexpected ')', at (string):1:159`