The use of `importlib.util` after importing just `importlib` breaks `hatchling version` and plugins

[krassowski]

importlib.util is used in get_source_meta() method here:

hatch/backend/src/hatchling/version/source/code.py

Lines 47 to 48 in d167faa

	spec = importlib.util.spec_from_file_location(os.path.splitext(path)[0], path) # type: ignore
	module = importlib.util.module_from_spec(spec) # type: ignore

but instead of importing importlib.util just importlib is imported:

hatch/backend/src/hatchling/version/source/code.py

Lines 11 to 12 in d167faa

	def get_version_data(self) -> dict:
	import importlib

This often works if some other package has already imported importlib.utils, but there is no guarantee that it will work, and it does not work on a clean Python 3.11 installation. See this discussion: https://discuss.python.org/t/python3-11-importlib-no-longer-exposes-util/25641

JupyterLab Ci got hit by this recently in: jupyterlab/jupyterlab#15692

[krassowski]

This happens when running hatchling version in some environments.

[medmunds]

Also affects hooks — load_plugin_from_script in hatchling.plugin.utils has same problematic use of import importlib followed by call to importlib.util.…. And Python 3.8.18.

May have surfaced in the past week, because pluggy 1.4.0 cleaned up module-level import importlib.metadata, and I'm guessing that used to pull in in importlib.util along with it.

Example:

...
  File "/home/runner/work/django-anymail/django-anymail/.tox/.package/lib/python3.8/site-packages/hatchling/metadata/core.py", line 1557, in hooks
    configured_hooks[hook_name] = metadata_hook(self.root, config)
  File "/home/runner/work/django-anymail/django-anymail/.tox/.package/lib/python3.8/site-packages/hatchling/metadata/custom.py", line 35, in __new__
    hook_class = load_plugin_from_script(path, build_script, MetadataHookInterface, 'metadata_hook')  # type: ignore
  File "/home/runner/work/django-anymail/django-anymail/.tox/.package/lib/python3.8/site-packages/hatchling/plugin/utils.py", line 16, in load_plugin_from_script
    spec = importlib.util.spec_from_file_location(script_name, path)  # type: ignore
AttributeError: module 'importlib' has no attribute 'util'

[krassowski]

Thanks, I updated the title to reflect the additional information.

[medmunds]

Did a little more investigation, and confirmed that hatchling version and plugins are indeed broken with pluggy 1.4.0 released 2024-01-24. (The bug is in hatch's code as described here, but pluggy 1.3.0 and earlier inadvertently provided a workaround that was removed in pluggy 1.4.0.)