spago2nix-ree

• re-uses already built purescript dependencies.
• so you don't have to re-compile them for every change in your project.

• Create spago project

  spago init
  

• Add a default.nix like:

  { pkgs ? import <nixpkgs> { } }:
  let
    spago2nix-ree = import (builtins.fetchGit {
  
      url = "https://github.com/thought2/spago2nix-ree";
  
      # ... ideally you'd specify a concrete revision here
  
    }) { };
  
    spagoProject = spago2nix-ree.buildProject {
  
      src = ./.;
  
    };
  
  in pkgs.stdenv.mkDerivation {
  
    name = "my-project";
  
    buildCommand = ''
      ln -s ${spagoProject} $out
    '';
  
    buildInputs = [
      # Puts the CLI on the path in a nix shell
      spago2nix-ree.spago2nix-ree
    ];
  }

• Build it with nix

  nix-shell
  
  spago2nix-ree
  
  # creates spago-lock.json
  
  nix-build
  

You can also use buildProjectDependencies to just build the dependencies instead.

To see the main feature, edit one of your project source files and run nix-build again. Only your local modules get recompiled.

• buildProject

  { src                           # path
  , spagoLock                     # string
      ? src + "/spago-lock.json"
  }
  # returns: derivation (.spago/*, output/*)

• buildProjectDependencies

  { src                           # path
  , spagoLock                     # string
      ? src + "/spago-lock.json"
  }
  # returns: derivation (.spago/*, output/*)

• spago2nix-ree

  # derivation (bin/spago2nix-ree)

• justinwoo/spago2nix

  Aweseome tool that I used in many projects. However, for my usecase CI builds were not fast enough.