Devbox build unable to handle different versions of Go

[RickyGrassmuck]

Issue

When adding go_1_19 to my projects Devbox configuration, the devbox build command fails with the error

#0 38.04 error: collision between `/nix/store/i0rdvlkvc5sz0dr87s379j0i4xmnwrp5-go-1.18.4/bin/go' and `/nix/store/w205lbrnh8cm9680pqzw2pc07rhi43an-go-1.19/bin/go'
#0 38.15 error: builder for '/nix/store/9vrr8h6l7n1gjrl8ybb24qrvpbirvd33-devbox.drv' failed with exit code 25
------
error: failed to solve: executor failed running [/bin/sh -eux -o pipefail -c nix-env -if ./.devbox/gen/default.nix]: exit code: 100

Expected Result

A devbox container image that includes Go version 1.19

Additional Information

I dug into the code a bit and the issue is being caused by the language detection feature for Go. The Go planner builder does not contain any logic for detecting that a golang nix package has already been requested which results in both the go_1_19 and go Nix packages being added to the list of packages used for populating the default.nix and shell.nix template files.

Contents of devbox.json

{
  "packages": [
    "go_1_19"
  ]
}

Generated default.nix

let
  pkgs = import (fetchTarball {
    # Commit hash as of 2022-08-16
    # `git ls-remote https://github.com/nixos/nixpkgs nixos-unstable`
    url = "https://github.com/nixos/nixpkgs/archive/af9e00071d0971eb292fd5abef334e66eda3cb69.tar.gz";
    sha256 = "1mdwy0419m5i9ss6s5frbhgzgyccbwycxm5nal40c8486bai0hwy";
  }) {};
in with pkgs;
buildEnv {
  name = "devbox";
  paths = [
    go_1_19
  
    go
  ];
  pathsToLink = [ "/bin" ];
}

Generated shell.nix

let
  pkgs = import (fetchTarball {
    # Commit hash as of 2022-08-16
    # `git ls-remote https://github.com/nixos/nixpkgs nixos-unstable`
    url = "https://github.com/nixos/nixpkgs/archive/af9e00071d0971eb292fd5abef334e66eda3cb69.tar.gz";
    sha256 = "1mdwy0419m5i9ss6s5frbhgzgyccbwycxm5nal40c8486bai0hwy";
  }) {};
in with pkgs;
mkShell {
  shellHook =
    ''
      echo "Starting a devbox shell..."
      export name="devbox"
      export IN_NIX_SHELL=0
      export DEVBOX_SHELL_ENABLED=1
    '';
  packages = [
    go_1_19
  
    go
  ];
}

Possible Solutions

I started poking around at a solution for handling this and at first I was going to just add a check in the Go planner's IsRelevant() method when I realized that this problem will not be limited to just Golang. I can think of 2 different methods for addressing this:

1. Modify the Planner interface in a way that forwards user-specified packages to each languages Planner in a way that allows it to create it's build plan using the user-specified language version and removing that entry from the user-specified packages list
2. Implement language version detection in each planner (ie. parsing go.mod/pyproject.toml for versions) and add collision checking for user-specified packages elsewhere.

I figured I'd forgo sending in a PR since this probably warrants a discussion before deciding on how this situation is handled.

[loreto]

Thanks @RickyGrassmuck

We're discussing internally – we're leaning towards option 2.

[loreto]

This PR: #49 should fix this issue. It should make it in this week's release.

[loreto]

To be specific: it'll make it so you don't have to add go_1_19 manually, since devbox itself will use the right package based on your go.mod.

[loreto]

PR Merged. Closing. It'll come out in a release tomorrow.

I know there's still an issue around improving package collisions overall, but we'll deal with that separately.