%py-meson-python: respect jobserver

repos/spack_repo/builtin/build_systems/python.py

@@ -19,10 +19,12 @@
     build_system,
     classproperty,
     depends_on,
+    determine_number_of_jobs,
     execute_install_time_tests,
     extends,
     filter_file,
     find,
+    get_effective_jobs,
     has_shebang,
     join_path,
     path_contains_subdirectory,
@@ -313,7 +315,7 @@ def build_directory(self) -> str:
         """
         return self.pkg.stage.source_path
 
-    def config_settings(self, spec: Spec, prefix: Prefix) -> Mapping[str, object]:
+    def config_settings(self, spec: Spec, prefix: Prefix) -> Dict[str, object]:
         """Configuration settings to be passed to the PEP 517 build backend.
 
         Requires pip 22.1 or newer for keys that appear only a single time,
@@ -363,8 +365,18 @@ def install(self, pkg: PythonPackage, spec: Spec, prefix: Prefix) -> None:
         pip.add_default_arg("-m", "pip")
 
         args = PythonPipBuilder.std_args(pkg) + [f"--prefix={prefix}"]
-
-        for setting in _flatten_dict(self.config_settings(spec, prefix)):
+        config_settings = self.config_settings(spec, prefix)
+
+        # Pass -jN for compile-args if supported and needed
+        if spec.satisfies("%py-pip@22.1: %py-meson-python@0.11:"):
+            # get_effective_jobs returns None when a jobserver is active, then we don't pass -j.
+            jobs = get_effective_jobs(
+                jobs=determine_number_of_jobs(parallel=pkg.parallel), supports_jobserver=True
+            )
+            if jobs is not None:
+                config_settings["compile-args"] = f"-j{jobs}"
+
+        for setting in _flatten_dict(config_settings):
             args.append(f"--config-settings={setting}")
         for option in self.install_options(spec, prefix):
             args.append(f"--install-option={option}")

repos/spack_repo/builtin/packages/py_matplotlib/package.py

@@ -300,7 +300,6 @@ def flag_handler(self, name, flags):
     def config_settings(self, spec, prefix):
         return {
             "builddir": "build",
-            "compile-args": f"-j{make_jobs}",
             "setup-args": {
                 "-Dsystem-freetype": True,
                 "-Dsystem-qhull": True,

repos/spack_repo/builtin/packages/py_numpy/package.py

@@ -337,7 +337,6 @@ def config_settings(self, spec, prefix):
 
         settings = {
             "builddir": "build",
-            "compile-args": f"-j{make_jobs}",
             "setup-args": {
                 # https://scipy.github.io/devdocs/building/blas_lapack.html
                 "-Dblas": blas,

repos/spack_repo/builtin/packages/py_scikit_learn/package.py

@@ -119,8 +119,9 @@ def url_for_version(self, version):
         return url.format(name, version)
 
     def setup_build_environment(self, env: EnvironmentModifications) -> None:
-        # Enable parallel builds of the sklearn backend
-        env.append_flags("SKLEARN_BUILD_PARALLEL", str(make_jobs))
+        if self.spec.satisfies("@:1.4"):
+            # Enable parallel builds for the pre py-meson-python build system
+            env.append_flags("SKLEARN_BUILD_PARALLEL", str(make_jobs))
 
         # https://scikit-learn.org/stable/developers/advanced_installation.html#macos
         if self.spec.satisfies("%apple-clang"):

repos/spack_repo/builtin/packages/py_scipy/package.py

@@ -227,7 +227,6 @@ def config_settings(self, spec, prefix):
 
         return {
             "builddir": "build",
-            "compile-args": f"-j{make_jobs}",
             "setup-args": {
                 # http://scipy.github.io/devdocs/building/blas_lapack.html
                 "-Dfortran_std": fortran_std,