Improve flake.nix to save build time, make nix run work again, and check builds on CI

.github/workflows/ci.yaml

@@ -118,3 +118,14 @@ jobs:
 
       - name: Run dialyzer
         run: mix dialyzer --format github
+
+  nix-build:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: nixbuild/nix-quick-install-action@v26
+      - run: nix build

flake.nix

@@ -1,124 +1,116 @@
 {
-  inputs = { nixpkgs.url = "github:NixOS/nixpkgs"; };
+  inputs = {nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";};
 
-  outputs = { self, nixpkgs }:
-    let
-      lib = nixpkgs.lib;
+  outputs = {
+    self,
+    nixpkgs,
+  }: let
+    inherit (nixpkgs) lib;
 
-      # Systems supported
-      allSystems = [
-        "x86_64-linux" # 64-bit Intel/AMD Linux
-        "aarch64-linux" # 64-bit ARM Linux
-        "x86_64-darwin" # 64-bit Intel macOS
-        "aarch64-darwin" # 64-bit ARM macOS
-      ];
-
-      pname = "next-ls";
-      version = "0.14.2"; # x-release-please-version
-      src = ./.;
-
-      # Helper to provide system-specific attributes
-      forAllSystems = f:
-        nixpkgs.lib.genAttrs allSystems (system:
-          let pkgs = import nixpkgs { inherit system; };
-          in f {
-            inherit pkgs;
-            # src = pkgs.fetchFromGitHub {
-            #   owner = "elixir-tools";
-            #   repo = "next-ls";
-            #  rev = "v${version}";
-            #  sha256 = "sha256-jpOInsr7Le0fjJZToNNrlNyXNF1MtF1kQONXdC2VsV0=";
-            # };
-            system = system;
-          });
-
-      burritoExe = system:
-        if system == "aarch64-darwin" then
-          "darwin_arm64"
-        else if system == "x86_64-darwin" then
-          "darwin_amd64"
-        else if system == "x86_64-linux" then
-          "linux_amd64"
-        else if system == "aarch64-linux" then
-          "linux_arm64"
-        else
-          "";
-    in {
-      packages = forAllSystems ({ pkgs, system }:
-        let
+    # Helper to provide system-specific attributes
+    forAllSystems = f:
+      nixpkgs.lib.genAttrs (builtins.attrNames burritoExe) (system:
+        f rec {
+          inherit system;
+          pkgs = nixpkgs.legacyPackages.${system};
           beamPackages = pkgs.beam.packages.erlang_26;
-          build = type:
-            beamPackages.mixRelease {
-              inherit pname version src;
-              erlang = beamPackages.erlang;
-              elixir = beamPackages.elixir_1_15;
+          elixir = beamPackages.elixir_1_15;
+        });
 
-              nativeBuildInputs = [ pkgs.xz pkgs.zig_0_11 pkgs._7zz ];
+    burritoExe = {
+      "aarch64-darwin" = "darwin_arm64";
+      "x86_64-darwin" = "darwin_amd64";
+      "x86_64-linux" = "linux_amd64";
+      "aarch64-linux" = "linux_arm64";
+    };
+  in {
+    packages = forAllSystems ({
+      pkgs,
+      system,
+      beamPackages,
+      elixir,
+    }: rec {
+      default = lib.makeOverridable ({
+        localBuild,
+        beamPackages,
+        elixir,
+      }:
+        beamPackages.mixRelease rec {
+          pname = "next-ls";
+          version = "0.14.2"; # x-release-please-version
+          src = self.outPath;
+          inherit (beamPackages) erlang;
+          inherit elixir;
 
-              mixFodDeps = beamPackages.fetchMixDeps {
-                inherit src version;
-                pname = "${pname}-deps";
-                hash = "sha256-ekB71eDfcFqC3JojFMnlGRQ/XiPwbUqFVor7ndpUd90=";
-              };
+          nativeBuildInputs = [pkgs.xz pkgs.zig_0_11 pkgs._7zz];
 
-              preConfigure = ''
-                bindir="$(pwd)/bin"
-                mkdir -p "$bindir"
-                echo '#!/usr/bin/env bash
-                7zz "$@"' > "$bindir/7z"
-                chmod +x "$bindir/7z"
+          mixFodDeps = beamPackages.fetchMixDeps {
+            inherit src version elixir;
+            pname = "${pname}-deps";
+            hash = "sha256-LV1DYmWi0Mcz1S5k77/jexXYqay7OpysCwOtUcafqGE=";
+          };
 
-                export HOME="$(pwd)"
-                export PATH="$bindir:$PATH"
-              '';
+          preConfigure = ''
+            bindir="$(pwd)/bin"
+            mkdir -p "$bindir"
+            echo '#!/usr/bin/env bash
+            7zz "$@"' > "$bindir/7z"
+            chmod +x "$bindir/7z"
 
-              preBuild = ''
-                export BURRITO_ERTS_PATH=${beamPackages.erlang}/lib/erlang
-              '';
+            export HOME="$(pwd)"
+            export PATH="$bindir:$PATH"
+          '';
 
-              preInstall = if type == "local" then ''
-                export BURRITO_TARGET="${burritoExe (system)}"
-              '' else
-                "";
+          preBuild = ''
+            export BURRITO_ERTS_PATH=${beamPackages.erlang}/lib/erlang
+          '';
 
-              postInstall = let
-                beforeCommand = ''
-                  chmod +x ./burrito_out/*
-                  cp -r ./burrito_out "$out"
-                '';
-                patchCommand = ''
-                  patchelf --set-interpreter ${pkgs.glibc}/lib/ld-linux-x86-64.so.2 "$out/burrito_out/next_ls_linux_amd64"
-                '';
-                afterCommand = ''
-                  rm -rf "$out/bin"
-                  mv "$out/burrito_out" "$out/bin"
-                  mv "$out/bin/next_ls_${burritoExe (system)}" "$out/bin/nextls"
-                '';
-              in beforeCommand
-              + lib.optionalString (system == "x86_64-linux") patchCommand
-              + afterCommand;
-            };
-        in {
-          default = build ("local");
-          ci = build ("ci");
-        });
+          preInstall = lib.optionalString localBuild ''
+            export BURRITO_TARGET="${burritoExe.${system}}"
+          '';
 
-      apps = forAllSystems ({ pkgs, system, ... }: {
-        default = {
-          type = "app";
-          program = "${self.packages.${system}.default}/burrito_out/next_ls_${
-              burritoExe (system)
-            }";
-        };
-      });
+          postInstall = ''
+            chmod +x ./burrito_out/*
+            cp -r ./burrito_out "$out"
+            ${lib.optionalString pkgs.stdenv.isLinux ''
+              patchelf --set-interpreter ${pkgs.stdenv.cc.libc}/lib/${
+                if system == "x86_64-linux"
+                then "ld-linux-x86-64.so.2"
+                else if system == "aarch64-linux"
+                then "ld-linux-aarch64.so.1"
+                else throw "unsupported Linux system"
+              } \
+              "$out/burrito_out/next_ls_${burritoExe.${system}}"
+            ''}
+            rm -rf "$out/bin"
+            mv "$out/burrito_out" "$out/bin"
+            mv "$out/bin/next_ls_${burritoExe.${system}}" "$out/bin/nextls"
+          '';
 
-      devShells = forAllSystems ({ pkgs, ... }:
-        let beamPackages = pkgs.beam.packages.erlang_26;
-        in {
-          default = pkgs.mkShell {
-            # The Nix packages provided in the environment
-            packages = [ beamPackages.erlang beamPackages.elixir_1_15 ];
+          meta = with lib; {
+            license = licenses.mit;
+            homepage = "https://www.elixir-tools.dev/next-ls/";
+            description = "The language server for Elixir that just works";
+            mainProgram = "nextls";
           };
-        });
-    };
+        }) {
+        inherit beamPackages elixir;
+        localBuild = true;
+      };
+
+      ci = default.override {localBuild = false;};
+    });
+
+    devShells = forAllSystems ({
+      pkgs,
+      beamPackages,
+      elixir,
+      ...
+    }: {
+      default = pkgs.mkShell {
+        # The Nix packages provided in the environment
+        packages = [beamPackages.erlang elixir];
+      };
+    });
+  };
 }