Print meson output in case of error during editable rebuild

mesonpy/_editable.py

@@ -340,11 +340,28 @@ def _rebuild(self) -> Node:
                 if self._work_to_do(env):
                     build_command = ' '.join(self._build_cmd)
                     print(f'meson-python: building {self._name}: {build_command}', flush=True)
-                    subprocess.run(self._build_cmd, cwd=self._build_path, env=env, check=True)
+                    subprocess.run(
+                        self._build_cmd,
+                        cwd=self._build_path,
+                        stdout=subprocess.PIPE,
+                        stderr=subprocess.STDOUT,
+                        env=env,
+                        check=True,
+                    )
             else:
-                subprocess.run(self._build_cmd, cwd=self._build_path, env=env, stdout=subprocess.DEVNULL, check=True)
+                subprocess.run(
+                    self._build_cmd,
+                    cwd=self._build_path,
+                    env=env,
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.STDOUT,
+                    check=True,
+                )
         except subprocess.CalledProcessError as exc:
-            raise ImportError(f're-building the {self._name} meson-python editable wheel package failed') from exc
+            output = exc.output.decode(errors='replace') if exc.output is not None else 'No error details available'
+            raise ImportError(
+                f're-building the {self._name} meson-python editable wheel package failed with: \n{output}'
+            ) from exc
 
         install_plan_path = os.path.join(self._build_path, 'meson-info', 'intro-install_plan.json')
         with open(install_plan_path, 'r', encoding='utf8') as f:

tests/test_editable.py

@@ -336,9 +336,52 @@ def test_editable_rebuild_error(package_purelib_and_platlib, tmp_path, verbose):
             # Import module and trigger rebuild: the build fails and ImportErrror is raised
             stdout = io.StringIO()
             with redirect_stdout(stdout):
-                with pytest.raises(ImportError, match='re-building the purelib-and-platlib '):
+                with pytest.raises(
+                    ImportError, match=r're-building the purelib-and-platlib (?s:.)*error: expected identifier'
+                ):
                     import plat  # noqa: F401
-            assert not verbose or stdout.getvalue().startswith('meson-python: building ')
+            if verbose:
+                assert stdout.getvalue().startswith('meson-python: building ')
+            else:
+                assert not stdout.getvalue()
+
+        finally:
+            del sys.meta_path[0]
+            sys.modules.pop('pure', None)
+            path.write_text(code)
+
+
+@pytest.mark.parametrize('verbose', [False, True], ids=('', 'verbose'))
+def test_editable_meson_file_rebuild_error(package_purelib_and_platlib, tmp_path, verbose):
+    with mesonpy._project({'builddir': os.fspath(tmp_path)}) as project:
+        finder = _editable.MesonpyMetaFinder(
+            project._metadata.name,
+            {'plat', 'pure'},
+            os.fspath(tmp_path),
+            project._build_command,
+            verbose=verbose,
+        )
+        path = package_purelib_and_platlib / 'meson.build'
+        code = path.read_text()
+
+        try:
+            # Install editable hooks
+            sys.meta_path.insert(0, finder)
+
+            # Insert invalid code in the meson build file
+            path.write_text('<not valid')
+
+            # Import module and trigger rebuild: the build fails and ImportErrror is raised
+            stdout = io.StringIO()
+            with redirect_stdout(stdout):
+                with pytest.raises(
+                    ImportError, match=r're-building the purelib-and-platlib (?s:.)*ERROR: Invalid source tree:'
+                ):
+                    import plat  # noqa: F401
+            if verbose:
+                assert stdout.getvalue().startswith('meson-python: building ')
+            else:
+                assert not stdout.getvalue()
 
         finally:
             del sys.meta_path[0]