linien-gui: fix build

pkgs/by-name/li/linien-gui/package.nix

@@ -4,15 +4,23 @@
   qt5,
 }:
 
-python3.pkgs.buildPythonApplication rec {
+let
+  python = python3.override {
+    self = python;
+    packageOverrides = self: super: {
+      numpy = super.numpy_1;
+    };
+  };
+in
+python.pkgs.buildPythonApplication rec {
   pname = "linien-gui";
   pyproject = true;
 
-  inherit (python3.pkgs.linien-common) src version;
+  inherit (python.pkgs.linien-common) src version;
 
   sourceRoot = "${src.name}/linien-gui";
 
-  build-system = with python3.pkgs; [
+  build-system = with python.pkgs; [
     setuptools
   ];
   nativeBuildInputs = [
@@ -25,7 +33,7 @@ python3.pkgs.buildPythonApplication rec {
     qt5.qtwayland
   ];
 
-  dependencies = with python3.pkgs; [
+  dependencies = with python.pkgs; [
     appdirs
     click
     pyqtgraph
@@ -41,6 +49,12 @@ python3.pkgs.buildPythonApplication rec {
     makeWrapperArgs+=("''${qtWrapperArgs[@]}")
   '';
 
+  passthru = {
+    # Useful for creating .withPackages environments, see NOTE near
+    # `python3Packages.linien-common.meta.broken`.
+    inherit python;
+  };
+
   meta = {
     description = "Graphical user interface of the Linien spectroscopy lock application";
     mainProgram = "linien";

pkgs/development/python-modules/linien-common/default.nix

@@ -70,19 +70,21 @@ buildPythonPackage rec {
     #
     # To evaluate this package with python3.withPackages, use:
     #
-    # pythonEnv = python3.override {
-    #   packageOverrides = self: super: {
-    #     numpy = super.numpy_1;
-    #   };
-    # }.withPackages(ps: {
+    # pythonEnv = pkgs.linien-gui.passthru.python.withPackages(ps: {
     #   ps.linien-common
     #   # Other packages...
     # });
     #
     # NOTE that the above Python environment will use Numpy 1 throughout all
-    # packages wrapped there, and this may trigger rebuilds for dependencies
-    # that depend on Numpy too. Be ready to also add more `packageOverrides` to
-    # make sure these other dependencies do build with numpy_1.
+    # packages wrapped there (see expression in linien-gui), and this may
+    # trigger rebuilds for dependencies that depend on Numpy too. Be ready to
+    # also add more `packageOverrides` to make sure these other dependencies do
+    # build with numpy_1.
+    #
+    # Last NOTE: If you need more packageOverrides besides those provided in
+    # the `linien-gui` expression, beware of:
+    #
+    # - https://github.com/NixOS/nixpkgs/issues/44426
     broken = lib.versionAtLeast numpy.version "2";
   };
 }