Seamless Cachix use in Nix shell?

l0b0 · May 10, 2023, 2:15am

How do I set up a shell.nix so that when running nix-shell it seamlessly uses my Cachix cache? That is, someone downloads my repo, runs nix-shell, and it uses the Cachix cache without any further setup?

ryantm · May 10, 2023, 2:45am

It’s not entirely seamless because the person has to run a special flag to accept the config but take a look at this:

github.com

nix-community/infra/blob/8fd3b4da2ab1fb8d5cab27651a4af8ce74d7e010/flake.nix#L4-L11

    
      
          nixConfig.extra-substituters = [
            "https://nix-community.cachix.org"
            "https://nixpkgs-update.cachix.org"
          ];
          nixConfig.extra-trusted-public-keys = [
            "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
            "nixpkgs-update.cachix.org-1:6y6Z2JdoL3APdu6/+Iy8eZX2ajf09e4EE9SnxSML1W8="
          ];

l0b0 · May 10, 2023, 3:28am

Thanks for the suggestion. Which flag do you mean? Also, do flakes work with nix-shell?

ryantm · May 10, 2023, 4:32am

Oh, oops no. They work with nix develop.

It tells you the flag when you run it without it. It is --accept-flake-config. nix develop - Nix Reference Manual