more information in case of error (#7784)

src/poetry/inspection/info.py

@@ -623,7 +623,7 @@ def get_pep517_metadata(path: Path) -> PackageInfo:
                 info = PackageInfo.from_metadata(path)
                 info = PackageInfo.from_metadata(path)
             except EnvCommandError as fbe:
             except EnvCommandError as fbe:
                 raise PackageInfoError(
                 raise PackageInfoError(
-                    path, "Fallback egg_info generation failed.", fbe
+                    path, e, "Fallback egg_info generation failed.", fbe
                 )
                 )
             finally:
             finally:
                 os.chdir(cwd)
                 os.chdir(cwd)

tests/inspection/test_info.py

@@ -250,12 +250,8 @@ def test_info_setup_missing_mandatory_should_trigger_pep517(
     setup_py.write_text(decode(setup))
     setup_py.write_text(decode(setup))
 
 
     spy = mocker.spy(VirtualEnv, "run")
     spy = mocker.spy(VirtualEnv, "run")
-    try:
-        PackageInfo.from_directory(source_dir)
-    except PackageInfoError:
-        assert spy.call_count == 3
-    else:
-        assert spy.call_count == 1
+    _ = PackageInfo.from_directory(source_dir)
+    assert spy.call_count == 1
 
 
 
 
 def test_info_prefer_poetry_config_over_egg_info():
 def test_info_prefer_poetry_config_over_egg_info():