Improve error reporting for build backend errors - TODO squash into o…

…ther error handling commit

src/poetry/installation/chef.py

@@ -121,32 +121,40 @@ def _prepare(
                 runner=quiet_subprocess_runner,
             )
             env.install(builder.build_system_requires)
-            env.install(
-                builder.build_system_requires | builder.get_requires_for_build("wheel")
-            )
 
             stdout = StringIO()
             error: Exception | None = None
             try:
                 with redirect_stdout(stdout):
+                    env.install(
+                        builder.build_system_requires
+                        | builder.get_requires_for_build("wheel")
+                    )
                     path = Path(
                         builder.build(
                             "wheel" if not editable else "editable",
                             destination.as_posix(),
                         )
                     )
             except BuildBackendException as e:
+                disclaimer = (
+                    "Note: This error originates from the build backend,"
+                    " and is likely not a problem with poetry"
+                    " but the concerning package not supporting PEP 517 builds."
+                    " You can verify this by running"
+                    " 'pip wheel --use-pep517 <concerning package>'."
+                )
+                message_parts = [disclaimer, str(e)]
                 if isinstance(e.exception, CalledProcessError) and (
                     e.exception.stdout is not None or e.exception.stderr is not None
                 ):
-                    message = (
+                    message_parts.append(
                         e.exception.stderr.decode()
                         if e.exception.stderr is not None
                         else e.exception.stdout.decode()
                     )
-                    error = ChefBuildError(message)
-                else:
-                    error = ChefBuildError(str(e))
+
+                error = ChefBuildError("\n\n".join(message_parts))
 
             if error is not None:
                 raise error from None

tests/installation/test_executor.py

@@ -909,7 +909,9 @@ def test_executor_fallback_on_poetry_create_error_without_wheel_installer(
     assert mock_pip_install.call_args[1].get("editable") is False
 
 
+@pytest.mark.parametrize("failing_method", ["build", "get_requires_for_build"])
 def test_build_backend_errors_are_reported_correctly_if_caused_by_subprocess(
+    failing_method: str,
     mocker: MockerFixture,
     config: Config,
     pool: RepositoryPool,
@@ -923,7 +925,7 @@ def test_build_backend_errors_are_reported_correctly_if_caused_by_subprocess(
     error = BuildBackendException(
         CalledProcessError(1, ["pip"], output=b"Error on stdout")
     )
-    mocker.patch.object(ProjectBuilder, "build", side_effect=error)
+    mocker.patch.object(ProjectBuilder, failing_method, side_effect=error)
     io.set_verbosity(Verbosity.NORMAL)
 
     executor = Executor(env, pool, config, io)
@@ -953,6 +955,14 @@ def test_build_backend_errors_are_reported_correctly_if_caused_by_subprocess(
 
   ChefBuildError
 
+  Note: This error originates from the build backend, and is likely not a problem with \
+poetry but the concerning package not supporting PEP 517 builds. You can verify this \
+by running 'pip wheel --use-pep517 <concerning package>'.
+  \
+
+  Backend operation failed: CalledProcessError(1, ['pip'])
+  \
+
   Error on stdout
 """