cura5: rework to include desktop item

Flake lock file updates:

• Updated input 'flake-utils':
    'github:numtide/flake-utils/f9e7cf818399d17d347f847525c5a5a8032e4e44' (2023-08-23)
  → 'github:numtide/flake-utils/ff7b65b44d01cf9ba6a71320833626af21126384' (2023-09-12)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/78058d810644f5ed276804ce7ea9e82d92bee293' (2023-09-10)
  → 'github:NixOS/nixpkgs/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db' (2023-09-17)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.github/workflows/build.yml

@@ -14,8 +14,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+        uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v23
       - name: Check ${{ matrix.check }}
         # Depends on nixos/nix#7759 to simply `nix flake check`
         run: nix run .#checks.$(nix eval --raw --impure --expr "builtins.currentSystem").${{ matrix.check }}
@@ -43,9 +43,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Install nix
-      uses: cachix/install-nix-action@v22
+      uses: cachix/install-nix-action@v23
     - name: Show nixpkgs version
       run: nix eval --impure --expr '(import ./flake-compat.nix { src = ./.; }).lib.version'
     - name: Setup cachix

.github/workflows/update.yml

@@ -11,8 +11,8 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+        uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v23
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}

callUnitRoot.nix

@@ -1,15 +0,0 @@
-{ pkgs
-, lib ? pkgs.lib
-, unitDir ? "unit"
-, packageFun ? "package.nix"
-, root ? "${./pkgs}/${unitDir}"
-}:
-let
-  shards = lib.attrNames (builtins.readDir root);
-  namesForShard = shard: lib.mapAttrs'
-    (name: _: { inherit name; value = root + "/${shard}/${name}"; })
-    (builtins.readDir (root + "/${shard}"));
-  namesToPath = lib.foldl' lib.recursiveUpdate { } (map namesForShard shards);
-  units = lib.mapAttrs (_: path: pkgs.callPackage (path + "/${packageFun}") { }) namesToPath;
-in
-units

default.nix

@@ -8,10 +8,10 @@
 
 { pkgs ? import <nixpkgs> { } }:
 let
-  legacy = import ./pkgs/top-level/all-packages.nix { inherit pkgs; };
-  units = import ./callUnitRoot.nix { inherit pkgs; root = ./pkgs/unit; };
+  system = pkgs.stdenv.hostPlatform.system;
+  packages = import ./pkgs/top-level { localSystem = system; inherit pkgs; };
 in
-legacy // units // {
+packages // {
   # The `lib`, `modules`, and `overlay` names are special
   lib = import ./lib { inherit pkgs; }; # functions
   modules = import ./modules; # NixOS modules

flake.lock

@@ -5,11 +5,11 @@
         "systems": "systems"
       },
       "locked": {
-        "lastModified": 1692799911,
-        "narHash": "sha256-3eihraek4qL744EvQXsK1Ha6C3CR7nnT8X2qWap4RNk=",
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "f9e7cf818399d17d347f847525c5a5a8032e4e44",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
         "type": "github"
       },
       "original": {
@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1693145325,
-        "narHash": "sha256-Gat9xskErH1zOcLjYMhSDBo0JTBZKfGS0xJlIRnj6Rc=",
+        "lastModified": 1694948089,
+        "narHash": "sha256-d2B282GmQ9o8klc22/Rbbbj6r99EnELQpOQjWMyv0rU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "cddebdb60de376c1bdb7a4e6ee3d98355453fe56",
+        "rev": "5148520bfab61f99fd25fb9ff7bfbb50dad3c9db",
         "type": "github"
       },
       "original": {

flake.nix

@@ -15,16 +15,7 @@
           pkgs = import nixpkgs { inherit system; };
         in
         {
-          # nixos/rfcs#140
-          # Only produces the package set of the proposed functionality.
-          # Unstable names are variables.
-          packages =
-            let
-              legacyPackages = import ./pkgs/top-level/all-packages.nix { inherit pkgs; };
-              unitPackages = import ./callUnitRoot.nix { inherit pkgs; };
-              onlyAvailable = lib.filterAttrs (_: drv: builtins.elem system (drv.meta.platforms or [ ]));
-            in
-            onlyAvailable (legacyPackages // unitPackages);
+          packages = import ./pkgs/top-level { localSystem = system; inherit pkgs; };
 
           checks = {
             nixpkgs-fmt = pkgs.writeShellScriptBin "nixpkgs-fmt-check" ''

pkgs/by-name/cu/cura5/package.nix

@@ -0,0 +1,94 @@
+{ lib
+, stdenv
+, fetchurl
+, writeScriptBin
+, appimageTools
+, copyDesktopItems
+, makeDesktopItem
+}:
+
+let
+  pname = "cura5";
+  version = "5.4.0";
+  name = "${pname}-${version}";
+
+  cura5 = appimageTools.wrapType2 {
+    inherit pname version;
+    src = fetchurl {
+      url = "https://github.com/Ultimaker/Cura/releases/download/${version}/Ultimaker-Cura-${version}-linux-modern.AppImage";
+      hash = "sha256-QVv7Wkfo082PH6n6rpsB79st2xK2+Np9ivBg/PYZd74=";
+    };
+    extraPkgs = _: [ ];
+  };
+  script = writeScriptBin pname ''
+    #!${stdenv.shell}
+    # AppImage version of Cura loses current working directory and treats all paths relateive to $HOME.
+    # So we convert each of the files passed as argument to an absolute path.
+    # This fixes use cases like `cd /path/to/my/files; cura mymodel.stl anothermodel.stl`.
+
+    args=()
+    for a in "$@"; do
+      if [ -e "$a" ]; then
+        a="$(realpath "$a")"
+      fi
+      args+=("$a")
+    done
+    exec "${cura5}/bin/${name}" "''${args[@]}"
+  '';
+in
+stdenv.mkDerivation rec {
+  inherit pname version;
+  dontUnpack = true;
+
+  nativeBuildInputs = [ copyDesktopItems ];
+  desktopItems = [
+    # Based on upstream.
+    # https://github.com/Ultimaker/Cura/blob/main/packaging/AppImage/cura.desktop.jinja
+    (makeDesktopItem {
+      name = "cura";
+      desktopName = "UltiMaker Cura";
+      genericName = "3D Printing Software";
+      comment = meta.longDescription;
+      exec = "cura5";
+      icon = "cura-icon";
+      terminal = false;
+      type = "Application";
+      mimeTypes = [
+        "model/stl"
+        "application/vnd.ms-3mfdocument"
+        "application/prs.wavefront-obj"
+        "image/bmp"
+        "image/gif"
+        "image/jpeg"
+        "image/png"
+        "text/x-gcode"
+        "application/x-amf"
+        "application/x-ply"
+        "application/x-ctm"
+        "model/vnd.collada+xml"
+        "model/gltf-binary"
+        "model/gltf+json"
+        "model/vnd.collada+xml+zip"
+      ];
+      categories = [ "Graphics" ];
+      keywords = [ "3D" "Printing" ];
+    })
+  ];
+
+  # TODO: Extract cura-icon from AppImage source.
+  installPhase = ''
+    mkdir -p $out/bin
+    cp ${script}/bin/cura5 $out/bin/cura5
+    runHook postInstall
+  '';
+
+  meta = {
+    description = "3D printing software";
+    homepage = "https://github.com/ultimaker/cura";
+    longDescription = ''
+      Cura converts 3D models into paths for a 3D printer. It prepares your print for maximum accuracy, minimum printing time and good reliability with many extra features that make your print come out great.
+    '';
+    license = lib.licenses.lgpl3;
+    platforms = [ "x86_64-linux" ];
+  };
+}

pkgs/top-level/by-name-overlay.nix

@@ -0,0 +1,56 @@
+# This file turns the pkgs/by-name directory (see its README.md for more info)
+# into an overlay that adds all the defined packages.
+#
+# No validity checks are done here, instead this file is optimised for
+# performance, and validity checks are done by CI on PRs.
+#
+# This file is based on Nixpkgs' `pkgs/top-level/by-name-overlay.nix` in order
+# to utilise the same infrastructure and layout, with some adjustments to fit
+# our derivative project.
+
+{ lib
+, pkgs
+}:
+
+# Type: Path -> Overlay
+baseDirectory:
+let
+  inherit (builtins)
+    readDir
+    ;
+
+  inherit (lib.attrsets)
+    mapAttrs
+    mapAttrsToList
+    mergeAttrsList
+    ;
+
+  # Package files for a single shard
+  # Type: String -> String -> AttrsOf Path
+  namesForShard = shard: type:
+    if type != "directory" then
+    # Ignore all non-directories. Technically only README.md is allowed as a file in the base directory, so we could alternatively:
+    # - Assume that README.md is the only file and change the condition to `shard == "README.md"` for a minor performance improvement.
+    #   This would however cause very poor error messages if there's other files.
+    # - Ensure that README.md is the only file, throwing a better error message if that's not the case.
+    #   However this would make for a poor code architecture, because one type of error would have to be duplicated in the validity checks and here.
+    # Additionally in either of those alternatives, we would have to duplicate the hardcoding of "README.md"
+      { }
+    else
+      mapAttrs
+        (name: _: baseDirectory + "/${shard}/${name}/package.nix")
+        (readDir (baseDirectory + "/${shard}"));
+
+  # The attribute set mapping names to the package files defining them
+  # This is defined up here in order to allow reuse of the value (it's kind of expensive to compute)
+  # if the overlay has to be applied multiple times
+  packageFiles = mergeAttrsList (mapAttrsToList namesForShard (readDir baseDirectory));
+in
+# TODO: Consider optimising this using `builtins.deepSeq packageFiles`,
+  # which could free up the above thunks and reduce GC times.
+  # Currently this would be hard to measure until we have more packages
+  # and ideally https://github.com/NixOS/nix/pull/8895
+_self: _super:
+mapAttrs
+  (_name: file: pkgs.callPackage file { })
+  packageFiles

pkgs/top-level/default.nix

@@ -0,0 +1,19 @@
+# Composes the packages collection.
+
+{
+  # The system packages will be build and used on.
+  localSystem
+  # Nixpkgs
+, pkgs
+  # Nixpkgs lib
+, lib ? pkgs.lib
+}:
+let
+  allPackages = import ./stage.nix {
+    inherit lib pkgs;
+  };
+
+  available = lib.filterAttrs
+    (_: drv: builtins.elem localSystem (drv.meta.platforms or [ ]));
+in
+available allPackages

pkgs/top-level/stage.nix

@@ -0,0 +1,24 @@
+# Composes a single bootstrapping of the package collection. The result is a set
+# of all the packages for some particular platform.
+
+{ lib
+, pkgs
+}:
+let
+
+  # An overlay to auto-call packages in .../by-name.
+  autoCalledPackages =
+    import ./by-name-overlay.nix { inherit pkgs lib; } ../by-name;
+
+  allPackages = _self: _super:
+    import ./all-packages.nix { inherit pkgs; };
+
+  toFix = (lib.flip lib.composeManyExtensions) (_self: { }) [
+    autoCalledPackages
+    allPackages
+  ];
+
+in
+
+# Return the complete set of packages.
+lib.fix toFix

pkgs/unit/cu/cura5/package.nix

@@ -1,39 +0,0 @@
-{ stdenv
-, fetchurl
-, writeScriptBin
-, appimageTools
-}:
-
-let
-  pname = "cura5";
-  version = "5.4.0";
-  name = "${pname}-${version}";
-
-  cura5 = appimageTools.wrapType2 {
-    inherit pname version;
-    src = fetchurl {
-      url = "https://github.com/Ultimaker/Cura/releases/download/${version}/Ultimaker-Cura-${version}-linux-modern.AppImage";
-      hash = "sha256-QVv7Wkfo082PH6n6rpsB79st2xK2+Np9ivBg/PYZd74=";
-    };
-    extraPkgs = _: [ ];
-  };
-  script = writeScriptBin pname ''
-    #!${stdenv.shell}
-    # AppImage version of Cura loses current working directory and treats all paths relateive to $HOME.
-    # So we convert each of the files passed as argument to an absolute path.
-    # This fixes use cases like `cd /path/to/my/files; cura mymodel.stl anothermodel.stl`.
-
-    args=()
-    for a in "$@"; do
-      if [ -e "$a" ]; then
-        a="$(realpath "$a")"
-      fi
-      args+=("$a")
-    done
-    exec "${cura5}/bin/${name}" "''${args[@]}"
-  '';
-in
-script // {
-  inherit name pname version;
-  meta.platforms = [ "x86_64-linux" ];
-}