fix(pip): add read permissions when extracting wheels (#3555)

Fix for wheels like
https://files.pythonhosted.org/packages/ad/39/da8b5c0f875ccb1770349caaecd87a253949ccbcdc2c869929919d744551/ag_ui_adk-0.4.2-py3-none-any.whl
where the contents do not have the read bit set.

Fixes #3554

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Richard Levasseur <rlevasseur@google.com>
(cherry picked from commit 96a1653)

Author: 3 people

python/private/pypi/whl_extract.bzl

@@ -19,6 +19,23 @@ def whl_extract(rctx, *, whl_path, logger):
         output = install_dir_path,
         supports_whl_extraction = rp_config.supports_whl_extraction,
     )
+
+    # Fix permissions on extracted files. Some wheels have files without read permissions set,
+    # which causes errors when trying to read them later.
+    os_name = repo_utils.get_platforms_os_name(rctx)
+    if os_name != "windows":
+        # On Unix-like systems, recursively add read permissions to all files
+        # and ensure directories are traversable (need execute permission)
+        result = repo_utils.execute_unchecked(
+            rctx,
+            op = "Fixing wheel permissions {}".format(whl_path),
+            arguments = ["chmod", "-R", "a+rX", str(install_dir_path)],
+            logger = logger,
+        )
+        if result.return_code != 0:
+            # It's possible chmod is not available or the filesystem doesn't support it.
+            # This is fine, we just want to try to fix permissions if possible.
+            logger.warn(lambda: "Failed to fix file permissions: {}".format(result.stderr))
     metadata_file = find_whl_metadata(
         install_dir = install_dir_path,
         logger = logger,