Cleanup Python package overrides.

distros/distro-overlay.nix

@@ -1,15 +1,11 @@
 { version, distro, python }:
 self: super:
 let
-  pythonOverridesFor = with self.lib; superPython: fix (python: superPython.override ({
-    packageOverrides ? _: _: {}, ...
-  }: {
-    self = python;
-    packageOverrides = composeExtensions packageOverrides
-      (pySelf: pySuper: optionalAttrs pySuper.isPy3k {
-        wxPython = pySelf.wxPython_4_0;
-      });
-  }));
+  pythonOverridesFor = with self.lib; prevPython: prevPython // {
+    pkgs = prevPython.pkgs.overrideScope (pyFinal: pyPrev: optionalAttrs pyPrev.isPy3k {
+      wxPython = pyFinal.wxPython_4_0;
+    });
+  };
 
   base = rosSelf: rosSuper: {
     recurseForDerivations = true;

distros/ros1-overlay.nix

@@ -51,28 +51,28 @@ rosSelf: rosSuper: with rosSelf.lib; {
     nativeBuildInputs = nativeBuildInputs ++ [ self.pkg-config ];
   });
 
+  # rviz does not support shiboken/pyside2 and SIP4 is broken with the latest
+  # pyqt5. This applies a patch to make pyqt5 compatible with SIP 4 and uses
+  # SIP 4 with python-qt-binding for rviz only.
   rviz = rosSuper.rviz.override {
     python-qt-binding = (rosSuper.python-qt-binding.override {
-      python3Packages = rosSelf.python3Packages.override {
-        overrides = pySelf: pySuper: {
-          pyqt5 = rosSelf.python3Packages.pyqt5.overrideAttrs ({
-            patches ? [], ...
-          }: {
-            patches = patches ++ [ (self.fetchpatch {
-              url = "https://aur.archlinux.org/cgit/aur.git/plain/restore-sip4-support.patch?h=python-pyqt5-sip4&id=6e712e6c588d550a1a6f83c1b37c2c9135aae6ba";
-              sha256 = "sha256-NfMe/EK1Uj88S82xZSm+A6js3PK9mlgsaci/kinlsy8=";
-            }) ];
-          });
-        };
-      };
+      python3Packages = rosSelf.python3Packages.overrideScope (pyFinal: pyPrev: {
+        pyqt5 = pyPrev.pyqt5.overrideAttrs ({
+          patches ? [], ...
+        }: {
+          patches = patches ++ [ (self.fetchpatch {
+            url = "https://aur.archlinux.org/cgit/aur.git/plain/restore-sip4-support.patch?h=python-pyqt5-sip4&id=6e712e6c588d550a1a6f83c1b37c2c9135aae6ba";
+            sha256 = "sha256-NfMe/EK1Uj88S82xZSm+A6js3PK9mlgsaci/kinlsy8=";
+          }) ];
+        });
+      });
     }).overrideAttrs({
       propagatedNativeBuildInputs ? [],
       postPatch ? "", ...
     }: {
-      # rviz1 does not support shiboken/pyside2
-      propagatedNativeBuildInputs = (rosSelf.lib.subtractLists
-        (with rosSelf.pythonPackages; [ shiboken2 pyside2 ])
-        propagatedNativeBuildInputs)  ++ [ rosSelf.pythonPackages.sip_4 ];
+      propagatedNativeBuildInputs = with rosSelf.pythonPackages;
+        (rosSelf.lib.subtractLists [ shiboken2 pyside2 ] propagatedNativeBuildInputs)
+        ++ [ sip_4 ];
       postPatch = ''
         sed -e "1 i\\import PyQt5" \
             -e "s#sipconfig\._pkg_config\['default_mod_dir'\], 'PyQt5'#PyQt5.__path__[0]#" \

modules/ros1/ros.nix

@@ -77,9 +77,9 @@ in {
   # Implementation
 
   config = mkIf cfg.enable {
-    # FIXME: mkAfter is used to make sure the Python overlay is applied. That
-    # means all other user configured Python overlays are ignored. This needs a
-    # fix in nixpkgs: https://github.com/NixOS/nixpkgs/issues/44426
+    # mkAfter is used to make sure the Python overlay (which uses overrideScope)
+    # is applied after any user overlays that use packageOverrides, so that
+    # composition works.
     nixpkgs.overlays = mkAfter (singleton (import ../../overlay.nix));
 
     services.ros = {

modules/ros2/ros.nix

@@ -69,9 +69,9 @@ in {
   # Implementation
 
   config = mkIf cfg.enable {
-    # FIXME: mkAfter is used to make sure the Python overlay is applied. That
-    # means all other user configured Python overlays are ignored. This needs a
-    # fix in nixpkgs: https://github.com/NixOS/nixpkgs/issues/44426
+    # mkAfter is used to make sure the Python overlay (which uses overrideScope)
+    # is applied after any user overlays that use packageOverrides, so that
+    # composition works.
     nixpkgs.overlays = mkAfter (singleton (import ../../overlay.nix));
 
     services.ros2.pkgs = mkDefault (pkgs.rosPackages."${cfg.distro}".overrideScope cfg.overlays);

pkgs/default.nix

@@ -1,60 +1,56 @@
 self: super: with self.lib; let
 
-  pythonOverridesFor = superPython: fix (python: superPython.override ({
-    packageOverrides ? _: _: {}, ...
-  }: {
-    self = python;
-    packageOverrides = composeExtensions packageOverrides (pySelf: pySuper: {
-      bson = pySelf.callPackage ./bson { };
+  pythonOverridesFor = prevPython: prevPython // {
+    pkgs = prevPython.pkgs.overrideScope (pyFinal: pyPrev: {
+      bson = pyFinal.callPackage ./bson { };
 
-      catkin-pkg = pySelf.callPackage ./catkin-pkg { };
+      catkin-pkg = pyFinal.callPackage ./catkin-pkg { };
 
-      catkin-tools = pySelf.callPackage ./catkin-tools { };
+      catkin-tools = pyFinal.callPackage ./catkin-tools { };
 
-      colcon-cargo = pySelf.callPackage ./colcon/cargo.nix { };
+      colcon-cargo = pyFinal.callPackage ./colcon/cargo.nix { };
 
-      colcon-cmake = pySelf.callPackage ./colcon/cmake.nix { };
+      colcon-cmake = pyFinal.callPackage ./colcon/cmake.nix { };
 
-      colcon-core = pySelf.callPackage ./colcon/core.nix { };
+      colcon-core = pyFinal.callPackage ./colcon/core.nix { };
 
-      colcon-library-path = pySelf.callPackage ./colcon/library-path.nix { };
+      colcon-library-path = pyFinal.callPackage ./colcon/library-path.nix { };
 
-      colcon-metadata = pySelf.callPackage ./colcon/metadata.nix { };
+      colcon-metadata = pyFinal.callPackage ./colcon/metadata.nix { };
 
-      colcon-notification = pySelf.callPackage ./colcon/notification.nix { };
+      colcon-notification = pyFinal.callPackage ./colcon/notification.nix { };
 
-      colcon-output = pySelf.callPackage ./colcon/output.nix { };
+      colcon-output = pyFinal.callPackage ./colcon/output.nix { };
 
-      colcon-package-information = pySelf.callPackage ./colcon/package-information.nix { };
+      colcon-package-information = pyFinal.callPackage ./colcon/package-information.nix { };
 
-      colcon-package-selection = pySelf.callPackage ./colcon/package-selection.nix { };
+      colcon-package-selection = pyFinal.callPackage ./colcon/package-selection.nix { };
 
-      colcon-parallel-executor = pySelf.callPackage ./colcon/parallel-executor.nix { };
+      colcon-parallel-executor = pyFinal.callPackage ./colcon/parallel-executor.nix { };
 
-      colcon-pkg-config = pySelf.callPackage ./colcon/pkg-config.nix { };
+      colcon-pkg-config = pyFinal.callPackage ./colcon/pkg-config.nix { };
 
-      colcon-python-setup-py = pySelf.callPackage ./colcon/python-setup-py.nix { };
+      colcon-python-setup-py = pyFinal.callPackage ./colcon/python-setup-py.nix { };
 
-      colcon-recursive-crawl = pySelf.callPackage ./colcon/recursive-crawl.nix { };
+      colcon-recursive-crawl = pyFinal.callPackage ./colcon/recursive-crawl.nix { };
 
-      colcon-ros = pySelf.callPackage ./colcon/ros.nix { };
+      colcon-ros = pyFinal.callPackage ./colcon/ros.nix { };
 
-      colcon-ros-cargo = pySelf.callPackage ./colcon/ros-cargo.nix { };
+      colcon-ros-cargo = pyFinal.callPackage ./colcon/ros-cargo.nix { };
 
-      colcon-test-result = pySelf.callPackage ./colcon/test-result.nix { };
+      colcon-test-result = pyFinal.callPackage ./colcon/test-result.nix { };
 
-      osrf-pycommon = pySelf.callPackage ./osrf-pycommon {};
+      osrf-pycommon = pyFinal.callPackage ./osrf-pycommon {};
 
-      rosdep = pySelf.callPackage ./rosdep { };
+      rosdep = pyFinal.callPackage ./rosdep { };
 
-      rosdistro = pySelf.callPackage ./rosdistro { };
+      rosdistro = pyFinal.callPackage ./rosdistro { };
 
-      rosinstall-generator = pySelf.callPackage ./rosinstall-generator { };
+      rosinstall-generator = pyFinal.callPackage ./rosinstall-generator { };
 
-      rospkg = pySelf.callPackage ./rospkg { };
+      rospkg = pyFinal.callPackage ./rospkg { };
     });
-  }));
-
+  };
 in {
   cargo-ament-build = self.callPackage ./cargo-ament-build { };