Protect sphinx.ext.autodoc.get_sourcename against misbehaving __getattr__

[xmo-odoo]

Feature or Bugfix

• Bugfix (minor)

Problem

When a __getattr__ misbehaves on a top-level object, get_sourcename will fail taking down the entire build:

reading sources... [ 50%] index
reading sources... [100%] thing

Traceback (most recent call last):
  File "sphinx/cmd/build.py", line 280, in build_main
    app.build(args.force_all, filenames)
  File "sphinx/application.py", line 343, in build
    self.builder.build_update()
  File "sphinx/builders/__init__.py", line 295, in build_update
    len(to_build))
  File "sphinx/builders/__init__.py", line 307, in build
    updated_docnames = set(self.read())
  File "sphinx/builders/__init__.py", line 414, in read
    self._read_serial(docnames)
  File "sphinx/builders/__init__.py", line 435, in _read_serial
    self.read_doc(docname)
  File "sphinx/builders/__init__.py", line 475, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "sphinx/io.py", line 189, in read_doc
    pub.publish()
  File "docutils/core.py", line 218, in publish
    self.settings)
  File "sphinx/io.py", line 109, in read
    self.parse()
  File "docutils/readers/__init__.py", line 78, in parse
    self.parser.parse(self.input, document)
  File "sphinx/parsers.py", line 101, in parse
    self.statemachine.run(inputlines, document, inliner=self.inliner)
  File "docutils/parsers/rst/states.py", line 171, in run
    input_source=document['source'])
  File "docutils/statemachine.py", line 240, in run
    context, state, transitions)
  File "docutils/statemachine.py", line 451, in check_line
    return method(match, context, next_state)
  File "docutils/parsers/rst/states.py", line 2769, in underline
    self.section(title, source, style, lineno - 1, messages)
  File "docutils/parsers/rst/states.py", line 327, in section
    self.new_subsection(title, lineno, messages)
  File "docutils/parsers/rst/states.py", line 395, in new_subsection
    node=section_node, match_titles=True)
  File "docutils/parsers/rst/states.py", line 282, in nested_parse
    node=node, match_titles=match_titles)
  File "docutils/parsers/rst/states.py", line 196, in run
    results = StateMachineWS.run(self, input_lines, input_offset)
  File "docutils/statemachine.py", line 240, in run
    context, state, transitions)
  File "docutils/statemachine.py", line 451, in check_line
    return method(match, context, next_state)
  File "docutils/parsers/rst/states.py", line 2342, in explicit_markup
    nodelist, blank_finish = self.explicit_construct(match)
  File "docutils/parsers/rst/states.py", line 2354, in explicit_construct
    return method(self, expmatch)
  File "docutils/parsers/rst/states.py", line 2097, in directive
    directive_class, match, type_name, option_presets)
  File "docutils/parsers/rst/states.py", line 2146, in run_directive
    result = directive_instance.run()
  File "sphinx/ext/autodoc/directive.py", line 162, in run
    documenter.generate(more_content=self.content)
  File "sphinx/ext/autodoc/__init__.py", line 983, in generate
    self.document_members(all_members)
  File "sphinx/ext/autodoc/__init__.py", line 862, in document_members
    check_module=members_check_module and not isattr)
  File "sphinx/ext/autodoc/__init__.py", line 957, in generate
    sourcename = self.get_sourcename()
  File "sphinx/ext/autodoc/__init__.py", line 589, in get_sourcename
    getattr(self.object, '__qualname__', None)):
  File "werkzeug/local.py", line 348, in __getattr__
    return getattr(self._get_current_object(), name)
  File "werkzeug/local.py", line 307, in _get_current_object
    return self.__local()
  File "werkzeug/local.py", line 137, in _lookup
    raise RuntimeError("object unbound")
RuntimeError: object unbound

Exception occurred:
  File "werkzeug/local.py", line 137, in _lookup
    raise RuntimeError("object unbound")
RuntimeError: object unbound
The full traceback has been saved in /tmp/sphinx-err-6fv3b0or.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
make: *** [Makefile:20: html] Error 2

Here the failure is specifically related to sphinx-autodoc (correctly) trying to document a LocalProxy, which basically do not work when unbound.

Python file:

# src/thing.py
import werkzeug.local

_locals_stack = werkzeug.local.LocalStack()
local = _locals_stack()
"""
    A global proxy that always redirect to the current local object.
"""

Sphinx project generated via apidoc:

$ sphinx-apidoc --ext-autodoc -F -a -o doc src

Generated sphinx file:

-- doc/thing.rst
thing module
============

.. automodule:: thing
   :members:
   :undoc-members:
   :show-inheritance:

Detail

Sphinx already has a safe_getattr, which can handle every possible error. This results in a build warning and the item being undocumented rather than the entire build failing:

reading sources... [100%] thing                                                                                                                                                                                    
WARNING: error while formatting signature for thing.local: Handler <function record_typehints at 0x7f28ba54ff28> for event 'autodoc-process-signature' threw an exception (exception: object unbound)
looking for now-outdated files... none found

[tk0miya]

LGTM :-)