Allow symlinked Extension.depends to be auto-included by sdist

Author: abravalheri

setuptools/_path.py

@@ -1,6 +1,7 @@
 import os
 import sys
 from typing import Union
+from pathlib import Path
 
 _Path = Union[str, os.PathLike]
 
@@ -11,6 +12,14 @@ def ensure_directory(path):
  os.makedirs(dirname, exist_ok=True)
 
 
+def safe_samefile(path1: _Path, path2: _Path) -> bool:
+ """Similar to os.path.samefile but returns False instead of raising exception"""
+ try:
+ return os.path.samefile(path1, path2)
+ except OSError:
+ return False
+
+
 def same_path(p1: _Path, p2: _Path) -> bool:
  """Differs from os.path.samefile because it does not require paths to exist.
  Purely string based (no comparison between i-nodes).
@@ -35,3 +44,21 @@ def normpath(filename: _Path) -> str:
  # See pkg_resources.normalize_path for notes about cygwin
  file = os.path.abspath(filename) if sys.platform == 'cygwin' else filename
  return os.path.normcase(os.path.realpath(os.path.normpath(file)))
+
+
+def besteffort_internal_path(root: _Path, file: _Path) -> str:
+ """Process ``file`` and return an equivalent relative path contained into root
+ (POSIX style, with no ``..`` segments).
+ It may raise an ``ValueError`` if that is not possible.
+ If ``file`` is not absolute, it will be assumed to be relative to ``root``.
+ """
+ path = os.path.join(root, file) # will ignore root if file is absolute
+ resolved = Path(path).resolve()
+ logical = Path(os.path.abspath(path))
+
+ # Prefer logical paths, since a parent directory can be symlinked inside root
+ if same_path(resolved, logical) or safe_samefile(resolved, logical):
+ return logical.relative_to(root).as_posix()
+
+ # Since ``resolved`` is used, it makes sense to resolve root too.
+ return resolved.relative_to(Path(root).resolve()).as_posix()

setuptools/command/build_ext.py

@@ -11,6 +11,7 @@
 from distutils.sysconfig import customize_compiler, get_config_var
 from distutils import log
 
+from setuptools import _path
 from setuptools.errors import BaseError
 from setuptools.extension import Extension, Library
 
@@ -271,9 +272,7 @@ def _get_internal_depends(self) -> Iterator[str]:
  depends = (dep for ext in self.extensions for dep in ext.depends)
  for dep in depends:
  try:
- abs_path = (project_root / dep).resolve()
- # if dep is absolute, Path will ignore project_root
- yield abs_path.relative_to(project_root).as_posix()
+ yield _path.besteffort_internal_path(project_root, dep)
  except ValueError:
  log.warn(f"ignoring {dep} for distribution: outside of project dir")