Merge pull request #254547 from DavHau/fix-pyproject-build

python3.pkgs.pypaBuildHook: fix conflicts via propagated inputs

pkgs/development/interpreters/python/hooks/default.nix

@@ -66,7 +66,19 @@ in {
   pypaBuildHook = callPackage ({ makePythonHook, build, wheel }:
     makePythonHook {
       name = "pypa-build-hook.sh";
-      propagatedBuildInputs = [ build wheel ];
+      propagatedBuildInputs = [ wheel ];
+      substitutions = {
+        inherit build;
+      };
+      # A test to ensure that this hook never propagates any of its dependencies
+      #   into the build environment.
+      # This prevents false positive alerts raised by catchConflictsHook.
+      # Such conflicts don't happen within the standard nixpkgs python package
+      #   set, but in downstream projects that build packages depending on other
+      #   versions of this hook's dependencies.
+      passthru.tests = import ./pypa-build-hook-tests.nix {
+        inherit pythonForBuild runCommand;
+      };
     } ./pypa-build-hook.sh) {
       inherit (pythonForBuild.pkgs) build;
     };

pkgs/development/interpreters/python/hooks/pypa-build-hook-test.nix

@@ -0,0 +1,32 @@
+{ pythonForBuild, runCommand }: {
+  dont-propagate-conflicting-deps = let
+    # customize a package so that its store paths differs
+    mkConflict = pkg: pkg.overrideAttrs { some_modification = true; };
+    # minimal pyproject.toml for the example project
+    pyprojectToml = builtins.toFile "pyproject.toml" ''
+      [project]
+      name = "my-project"
+      version = "1.0.0"
+    '';
+    # the source of the example project
+    projectSource = runCommand "my-project-source" {} ''
+      mkdir -p $out/src
+      cp ${pyprojectToml} $out/pyproject.toml
+      touch $out/src/__init__.py
+    '';
+    in
+    # this build must never triger conflicts
+    pythonForBuild.pkgs.buildPythonPackage {
+      pname = "dont-propagate-conflicting-deps";
+      version = "0.0.0";
+      src = projectSource;
+      format = "pyproject";
+      propagatedBuildInputs = [
+        # At least one dependency of `build` should be included here to
+        # keep the test meaningful
+        (mkConflict pythonForBuild.pkgs.tomli)
+        # setuptools is also needed to build the example project
+        pythonForBuild.pkgs.setuptools
+      ];
+    };
+}

pkgs/development/interpreters/python/hooks/pypa-build-hook.sh

@@ -6,7 +6,7 @@ pypaBuildPhase() {
     runHook preBuild
 
     echo "Creating a wheel..."
-    pyproject-build --no-isolation --outdir dist/ --wheel $pypaBuildFlags
+    @build@/bin/pyproject-build --no-isolation --outdir dist/ --wheel $pypaBuildFlags
     echo "Finished creating a wheel..."
 
     runHook postBuild