pip_install: avoid assuming 'Root-Is-Purelib' is provided in all WHEEL files. https://github.com/bazelbuild/rules_python/issues/435 (#485)
diff --git a/python/pip_install/extract_wheels/lib/purelib.py b/python/pip_install/extract_wheels/lib/purelib.py
index 4e9eb3f..99e2c80 100644
--- a/python/pip_install/extract_wheels/lib/purelib.py
+++ b/python/pip_install/extract_wheels/lib/purelib.py
@@ -15,13 +15,9 @@
wheel_metadata_file_path = pathlib.Path(dist_info, "WHEEL")
wheel_metadata_dict = wheel.parse_wheel_meta_file(str(wheel_metadata_file_path))
- if "Root-Is-Purelib" not in wheel_metadata_dict:
- raise ValueError(
- "Invalid WHEEL file '%s'. Expected key 'Root-Is-Purelib'."
- % wheel_metadata_file_path
- )
- root_is_purelib = wheel_metadata_dict["Root-Is-Purelib"]
-
+ # It is not guaranteed that a WHEEL file author populates 'Root-Is-Purelib'.
+ # See: https://github.com/bazelbuild/rules_python/issues/435
+ root_is_purelib: str = wheel_metadata_dict.get("Root-Is-Purelib", "")
if root_is_purelib.lower() == "true":
# The Python package code is in the root of the Wheel, so no need to 'spread' anything.
return
