---
title: Guides and HOWTOs
---

How to do stuff.
==

Not much to see here.  Go to a subpage or read the hintlets below.

Using `nix-shell` relative to a different package set
--

Example, using GHC 9.8.1 from a PR before it was merged into Nixpkgs
proper.

```
nix-shell -I nixpkgs=https://github.com/vaibhavsagar/nixpkgs/archive/refs/heads/vaibhavsagar/ghc981.zip -p haskell.compiler.ghc981
```

Note that this is equivalent to running random code off the internet,
and that the above URL is not pinned at all.

Using ad-hoc packages from PyPI in `nix-shell`
--

Put something like this in your `shell.nix`:

```
{ pkgs ? import <nixpkgs> {} }:
let
  my-python-packages = ps: with ps; [
    (buildPythonPackage rec {
      pname = "futhark-data";
      version = "1.0.1";
      src = fetchPypi {
        inherit pname version;
        sha256 = "sha256-UJ0x642f5Q9749ffYIimQuF+sMTVOyx4iYZgrB86HFo=";
      };
      doCheck = false;
    })
    numpy
    scipy
  ];
  my-python = pkgs.python3.withPackages my-python-packages;
in my-python.env
```

[Taken from here.](https://nixos.wiki/wiki/Python)