Add '--lenient' option to reduce some errors to warnings

changelog/+24f6a8f8.feature.rst

@@ -0,0 +1,5 @@
+Add ``--lenient`` option to allow certain errors to be emitted as warnings
+instead of causing Twine to exit.
+
+Note that use of this option represents acknowledgement that uploads may fail
+through no fault of Twine!

tests/test_settings.py

@@ -81,7 +81,7 @@ def test_settings_transforms_repository_config_non_pypi(write_config_file):
     assert s.disable_progress_bar is False
 
 
-def test_settings_verify_feature_compatibility() -> None:
+def test_settings_verify_feature_compatibility(caplog) -> None:
     s = settings.Settings(skip_existing=True)
     s.repository_config = {"repository": repository.WAREHOUSE}
     try:
@@ -105,6 +105,18 @@ def test_settings_verify_feature_compatibility() -> None:
     with pytest.raises(exceptions.UnsupportedConfiguration):
         s.verify_feature_capability()
 
+    s.lenient = True
+    try:
+        s.verify_feature_capability()
+    except exceptions.UnsupportedConfiguration as unexpected_exc:
+        pytest.fail(
+            "Expected exception to be logged instead of raised, but"
+            f" {unexpected_exc!r} was raised"
+        )
+    assert len(caplog.messages) == 1
+    assert "Unsupported configuration" in caplog.messages[0]
+    s.lenient = False
+
     s.skip_existing = False
     try:
         s.verify_feature_capability()

twine/exceptions.py

@@ -111,15 +111,21 @@ def with_feature(self, feature: str) -> "UnsupportedConfiguration.Builder":
             return self
 
         def finalize(self) -> "UnsupportedConfiguration":
-            return UnsupportedConfiguration(
-                f"The configured repository {self.repository_url!r} does not "
-                "have support for the following features: "
-                f"{', '.join(self.features)} and is an unsupported "
-                "configuration",
+            return UnsupportedConfiguration.from_args(
                 self.repository_url,
-                *self.features,
+                self.features,
             )
 
+    @classmethod
+    def from_args(
+        cls, repository_url: str, features: t.List[str]
+    ) -> "UnsupportedConfiguration":
+        return cls(
+            f"The configured repository {repository_url!r} may not have"
+            f" support for the following features: {', '.join(features)}"
+            " and is an unsupported configuration."
+        )
+
 
 class UnreachableRepositoryURLDetected(TwineException):
     """An upload attempt was detected to a URL without a protocol prefix.

twine/settings.py

@@ -23,6 +23,8 @@
 from twine import repository
 from twine import utils
 
+logger = logging.getLogger(__name__)
+
 
 class Settings:
     """Object that manages the configuration for Twine.
@@ -61,6 +63,7 @@ def __init__(
         repository_url: Optional[str] = None,
         verbose: bool = False,
         disable_progress_bar: bool = False,
+        lenient: bool = False,
         **ignored_kwargs: Any,
     ) -> None:
         """Initialize our settings instance.
@@ -107,11 +110,14 @@ def __init__(
             Show verbose output.
         :param disable_progress_bar:
             Disable the progress bar.
+        :param lenient:
+            Emit some errors as warnings and attempt to keep going.
         """
         self.config_file = config_file
         self.comment = comment
         self.verbose = verbose
         self.disable_progress_bar = disable_progress_bar
+        self.lenient = lenient
         self.skip_existing = skip_existing
         self._handle_repository_options(
             repository_name=repository_name,
@@ -278,6 +284,13 @@ def register_argparse_arguments(parser: argparse.ArgumentParser) -> None:
             action="store_true",
             help="Disable the progress bar.",
         )
+        parser.add_argument(
+            "--lenient",
+            default=False,
+            required=False,
+            action="store_true",
+            help="Emit some errors as warnings and try to keep going.",
+        )
 
     @classmethod
     def from_argparse(cls, args: argparse.Namespace) -> "Settings":
@@ -325,12 +338,21 @@ def verify_feature_capability(self) -> None:
         """
         repository_url = cast(str, self.repository_config["repository"])
 
+        exc = None
         if self.skip_existing and not repository_url.startswith(
             (repository.WAREHOUSE, repository.TEST_WAREHOUSE)
         ):
-            raise exceptions.UnsupportedConfiguration.Builder().with_feature(
-                "--skip-existing"
-            ).with_repository_url(repository_url).finalize()
+            exc = (
+                exceptions.UnsupportedConfiguration.Builder()
+                .with_feature("--skip-existing")
+                .with_repository_url(repository_url)
+                .finalize()
+            )
+        if exc is not None:
+            if self.lenient:
+                logger.warning("Unsupported configuration: %s", exc)
+            else:
+                raise exc
 
     def check_repository_url(self) -> None:
         """Verify we are not using legacy PyPI.