repo: handle invalid distributions gracefully

This change ensures that poetry does not bail out when encountering a
bad distributions in `sys_path`. This behaviour is similar to how `pip`
handles this today. In addition to ignoring these distributions, we
also issue a warning log so users can choose to act on this.

Further, this change also handles a scenario where an empty path is
present in the `sys_path`.

src/poetry/repositories/installed_repository.py

@@ -2,6 +2,7 @@
 
 import itertools
 import json
+import logging
 
 from pathlib import Path
 from typing import TYPE_CHECKING
@@ -28,6 +29,9 @@
     FileNotFoundError = OSError
 
 
+logger = logging.getLogger(__name__)
+
+
 class InstalledRepository(Repository):
     @classmethod
     def get_package_paths(cls, env: Env, name: str) -> set[Path]:
@@ -233,20 +237,41 @@ def load(cls, env: Env, with_dependencies: bool = False) -> InstalledRepository:
 
         repo = cls()
         seen = set()
+        skipped = set()
 
         for entry in reversed(env.sys_path):
+            if not entry.strip():
+                logger.debug(
+                    "Project environment contains an empty path in <c1>sys_path</>,"
+                    " ignoring."
+                )
+                continue
+
             for distribution in sorted(
                 metadata.distributions(  # type: ignore[no-untyped-call]
                     path=[entry],
                 ),
                 key=lambda d: str(d._path),  # type: ignore[attr-defined]
             ):
-                name = canonicalize_name(distribution.metadata["name"])
+                path = Path(str(distribution._path))  # type: ignore[attr-defined]
 
-                if name in seen:
+                if path in skipped:
                     continue
 
-                path = Path(str(distribution._path))  # type: ignore[attr-defined]
+                try:
+                    name = canonicalize_name(distribution.metadata["name"])
+                except TypeError:
+                    logger.warning(
+                        "Project environment contains an invalid distribution"
+                        " (<c1>%s</>). Consider removing it manually or recreate the"
+                        " environment.",
+                        path,
+                    )
+                    skipped.add(path)
+                    continue
+
+                if name in seen:
+                    continue
 
                 try:
                     path.relative_to(_VENDORS)

tests/repositories/test_installed_repository.py

@@ -13,6 +13,7 @@
 
 
 if TYPE_CHECKING:
+    from _pytest.logging import LogCaptureFixture
     from poetry.core.packages.package import Package
     from pytest_mock.plugin import MockerFixture
 
@@ -103,6 +104,27 @@ def test_load_successful(repository: InstalledRepository):
     assert len(repository.packages) == len(INSTALLED_RESULTS) - 1
 
 
+def test_load_successful_with_invalid_distribution(
+    caplog: LogCaptureFixture, mocker: MockerFixture, env: MockEnv, tmp_dir: str
+) -> None:
+    invalid_dist_info = Path(tmp_dir) / "site-packages" / "invalid-0.1.0.dist-info"
+    invalid_dist_info.mkdir(parents=True)
+    mocker.patch(
+        "poetry.utils._compat.metadata.Distribution.discover",
+        return_value=INSTALLED_RESULTS + [metadata.PathDistribution(invalid_dist_info)],
+    )
+    repository_with_invalid_distribution = InstalledRepository.load(env)
+
+    assert (
+        len(repository_with_invalid_distribution.packages) == len(INSTALLED_RESULTS) - 1
+    )
+    assert len(caplog.messages) == 1
+
+    message = caplog.messages[0]
+    assert message.startswith("Project environment contains an invalid distribution")
+    assert str(invalid_dist_info) in message
+
+
 def test_load_ensure_isolation(repository: InstalledRepository):
     package = get_package_from_repository("attrs", repository)
     assert package is None