➜  nix-roc git:(main) nix develop
error:
       … while calling the 'derivationStrict' builtin

         at //builtin/derivation.nix:9:12: (source not available)

       … while evaluating derivation 'nix-shell'
         whose name attribute is located at /nix/store/z5gdynjj3h25xvdqpxski061qcvrpdik-source/pkgs/stdenv/generic/make-derivation.nix:300:7

       … while evaluating attribute 'buildInputs' of derivation 'nix-shell'

         at /nix/store/z5gdynjj3h25xvdqpxski061qcvrpdik-source/pkgs/stdenv/generic/make-derivation.nix:347:7:

          346|       depsHostHost                = lib.elemAt (lib.elemAt dependencies 1) 0;
          347|       buildInputs                 = lib.elemAt (lib.elemAt dependencies 1) 1;
             |       ^
          348|       depsTargetTarget            = lib.elemAt (lib.elemAt dependencies 2) 0;

       error: Dependency is not of a valid type: element 2 of buildInputs for nix-shell

git clone https://github.com/roc-lang/roc.git
cd roc
nix develop
cargo build --release --bin roc

let
  pkgs = import <nixpkgs> {};

  rocSrc = pkgs.fetchFromGitHub {
    owner = "roc-lang";
    repo = "roc";
    rev = "default-nix-env-var";
    sha256 = "sha256-nxGT2m0ftDslsgU8I2GZ72uPvtHEBE5wN9mJNu8X5Eo=";
  };

  roc = import rocSrc {};


in pkgs.mkShell {
  buildInputs = [
    pkgs.just
    roc
  ];
}

let
  pkgs = import <nixpkgs> {};

  # Fetch and extract the nightly tar
  rocNightlyTar = pkgs.fetchurl {
    url = "https://github.com/roc-lang/roc/releases/download/nightly/roc_nightly-linux_x86_64-latest.tar.gz";
    sha256 = "sha256-3RDVU+sMFVsThviZAI76DKn07fb8j6k8qGlBjUtby8o=";
  };

  rocNightly = pkgs.stdenv.mkDerivation {
    name = "roc";
    src = rocNightlyTar;
    installPhase = ''
      mkdir -p $out
      cp -R * $out/
    '';
  };


in pkgs.mkShell {
  buildInputs = [
    pkgs.just
  ];

  # make the `roc` command work
  shellHook = ''
    export PATH=$PATH:${rocNightly}
  '';
}

{
  description = "Devshell using the roc nightly.";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    # to easily make configs for multiple architectures
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    let
      supportedSystems = [ "x86_64-linux" ];
    in
      flake-utils.lib.eachSystem supportedSystems (system:
        let
            pkgs = import nixpkgs {
              inherit system;
            };

            rocNightlyTar = pkgs.fetchurl {
                url = "https://github.com/roc-lang/roc/releases/download/nightly/roc_nightly-linux_x86_64-latest.tar.gz";
                sha256 = "sha256-3RDVU+sMFVsThviZAI76DKn07fb8j6k8qGlBjUtby8o=";
            };

            rocNightly = pkgs.stdenv.mkDerivation {
                name = "roc";
                src = rocNightlyTar;
                installPhase = ''
                mkdir -p $out
                cp -R * $out/
                '';
            };
        in
            {
                devShell = pkgs.mkShell {
                    packages = [
                        pkgs.just
                        ];

                    shellHook = ''export PATH=$PATH:${rocNightly}'';
                };
            });
}

#!/usr/bin/env bash

# https://vaneyckt.io/posts/safer_bash_scripts_with_set_euxo_pipefail/
set -euxo pipefail

# URL to fetch and get the sha256 hash from
URL="https://github.com/roc-lang/roc/releases/download/nightly/roc_nightly-linux_x86_64-latest.tar.gz"

# Fetch the sha256 hash using nix-prefetch-url
SHA256=$(nix-prefetch-url --type sha256 "$URL")

# Check if we successfully got the hash
if [ -z "$SHA256" ]; then
    echo "Failed to fetch SHA256."
    exit 1
fi

# Update the sha256 in the default.nix file
# This time, we are replacing the entire sha256 value with the new one, without the "sha256-" prefix.
sed -i "s|sha256-.*\"|${SHA256}\"|" default.nix

echo "Updated sha256 in default.nix to $SHA256."

  inputs = {
    flake-utils.url = "github:numtide/flake-utils";
    roc.url = "github:roc-lang/roc";
  };

  outputs = { self, nixpkgs, flake-utils, roc }:
    let supportedSystems = with flake-utils.lib.system; [ x86_64-linux ];

    in flake-utils.lib.eachSystem supportedSystems (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        inherit (pkgs) lib stdenv callPackage;
      in {
        devShells.default = pkgs.mkShell {
          name = "devshell";
          buildInputs = [ roc.packages.${system}.default ];
        };
      });
}