Generating a Nix package from a stack project

Question

I have a software application that can be built and installed with stack. I would like to offer a binary package as well for Linux and Mac. For this purpose I'm considering nix, since, among other things, it can be used in Linux and Mac. This will save me the trouble of having to maintain two package types.

After reading about how nix packages are defined, I would expect that a stack based project could be built with a configuration that would look like:

{ stdenv, fetchurl, stack }: # we need to depend on stack

stdenv.mkDerivation { 
  name = "some-haskell-package-0.1"; 
  builder = ./builder.sh; # here we would call `stack install` 
  src = fetchurl {  # ...
  };
}

Looking at the resources available online, I cannot find any description of how this could be done. I don't know if this means that stack and nix are not intended to be used in this way.

The only thing I could find in the manual is how stack can use nix, and a stack to nix conversion tool.

I'm also open to alternatives for multi-platform packaging.

Answer 1

With this recent merge, I am able to build and installed a simple stack project using following steps:

1. Create new hello project with stack new hello

2. Add following lines to stack.yaml

   nix:
     enable: true
     shell-file: default.nix
   

3. Create default.nix

   with (import <nixpkgs> { });
   
   haskell.lib.buildStackProject {
     name = "hello";
     src = ./.;
   }
   

At this point, I am able to run nix-build to build the project and result will be at ./result/bin/hello-exe

If I want to install, I would run nix-env -i -f default.nix

---

Side note: nix-build will download stack's build plan every time it run.

I want to incrementally build my project while making changes so I mainly just drop in the shell and call stack build there.