Remove support for installed eggs distributions

news/12308.removal.rst

@@ -0,0 +1 @@
+Remove support for discovering installed ``egg`` distributions.

src/pip/_internal/metadata/importlib/_envs.py

@@ -1,4 +1,3 @@
-import functools
 import importlib.metadata
 import logging
 import os
@@ -12,7 +11,6 @@
 
 from pip._internal.metadata.base import BaseDistribution, BaseEnvironment
 from pip._internal.models.wheel import Wheel
-from pip._internal.utils.deprecation import deprecated
 from pip._internal.utils.filetypes import WHEEL_EXTENSION
 
 from ._compat import BadMetadata, BasePath, get_dist_name, get_info_location
@@ -131,29 +129,6 @@ def _find_eggs_in_zip(self, location: str) -> Iterator[BaseDistribution]:
  for dist in find_eggs_in_zip(importer, location):
  yield legacy.Distribution(dist)
 
- def find_eggs(self, location: str) -> Iterator[BaseDistribution]:
- """Find eggs in a location.
-
- This actually uses the old *pkg_resources* backend. We likely want to
- deprecate this so we can eventually remove the *pkg_resources*
- dependency entirely. Before that, this should first emit a deprecation
- warning for some versions when using the fallback since importing
- *pkg_resources* is slow for those who don't need it.
- """
- if os.path.isdir(location):
- yield from self._find_eggs_in_dir(location)
- if zipfile.is_zipfile(location):
- yield from self._find_eggs_in_zip(location)
-
-
-@functools.lru_cache(maxsize=None) # Warn a distribution exactly once.
-def _emit_egg_deprecation(location: Optional[str]) -> None:
- deprecated(
- reason=f"Loading egg at {location} is deprecated.",
- replacement="to use pip for package installation.",
- gone_in="23.3",
- )
-
 
 class Environment(BaseEnvironment):
  def __init__(self, paths: Sequence[str]) -> None:
@@ -173,9 +148,6 @@ def _iter_distributions(self) -> Iterator[BaseDistribution]:
  finder = _DistributionFinder()
  for location in self._paths:
  yield from finder.find(location)
- for dist in finder.find_eggs(location):
- _emit_egg_deprecation(dist.location)
- yield dist
  # This must go last because that's how pkg_resources tie-breaks.
  yield from finder.find_linked(location)