Shell.nix that depends on flake?

1

How does one write a shell.nix file that depends on a flake?

2

Instead of writing a shell.nix, consider adding a devShells.default attribute to your flake.nix outputs.

Alternatively, you could set a system channel in your flake and have the shell.nix reference that channel?

3

I think the main (only?) pattern here is to use builtins.getFlake.

Here’s a github code search with some examples of what people are doing.

I also used it for the last example in a blog post I wrote last month (just as an example I can speak for; it wasn’t the point of the post and it isn’t explained): avoid trap-clobbering in nix-shell

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4

I have a bunch of shell.nix files for different projects, and I don’t want to rewrite them all into flakes, so I’d like to be able to use flake outputs from within them.

Also applies to eg home-manager configs.

Thanks, I’ll give that a shot!

5

alternatively you can write a flake and use flake-compat to provide a shell.nix that will work with nix 2.3 https://github.com/edolstra/flake-compat/

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6

This worked for me:

let
  crunkurrent_flake = builtins.getFlake "github:samuela/crunkurrent";
  crunkurrent = crunkurrent_flake.packages."${builtins.currentSystem}".default;
in
pkgs.mkShell {
  buildInputs = [ crunkurrent ];
  ...
}
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