3.4.0 - 'ForwardRef' object has no attribute '__name__'

[tfranzel]

Describe the bug

Sphinx built broke today with 3.4.0. has been fine with 3.3.1

OK: https://travis-ci.org/github/tfranzel/drf-spectacular/jobs/750597777
Broken: https://travis-ci.org/github/tfranzel/drf-spectacular/jobs/750671324

To Reproduce

# Sphinx version: 3.4.0
# Python version: 3.8.5 (CPython)
# Docutils version: 0.16 release
# Jinja2 version: 2.11.2
# Last messages:
#   building [mo]: all of 0 po files
#   building [html]: all source files
#   updating environment:
#   [new config]
#   11 added, 0 changed, 0 removed
#   reading sources... [  9%] blueprints
#   reading sources... [ 18%] changelog
#   reading sources... [ 27%] client_generation
#   reading sources... [ 36%] customization
#   reading sources... [ 45%] drf_spectacular
# Loaded extensions:
#   sphinx.ext.mathjax (3.4.0) from PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/mathjax.py
#   sphinxcontrib.applehelp (1.0.2) from PATH/.tox/docs/lib/python3.8/site-packages/sphinxcontrib/applehelp/__init__.py
#   sphinxcontrib.devhelp (1.0.2) from PATH/.tox/docs/lib/python3.8/site-packages/sphinxcontrib/devhelp/__init__.py
#   sphinxcontrib.htmlhelp (1.0.3) from PATH/.tox/docs/lib/python3.8/site-packages/sphinxcontrib/htmlhelp/__init__.py
#   sphinxcontrib.serializinghtml (1.1.4) from PATH/.tox/docs/lib/python3.8/site-packages/sphinxcontrib/serializinghtml/__init__.py
#   sphinxcontrib.qthelp (1.0.3) from PATH/.tox/docs/lib/python3.8/site-packages/sphinxcontrib/qthelp/__init__.py
#   alabaster (0.7.12) from PATH/.tox/docs/lib/python3.8/site-packages/alabaster/__init__.py
#   sphinx.ext.autodoc.type_comment (3.4.0) from PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/type_comment.py
#   sphinx.ext.autodoc (3.4.0) from PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py
Traceback (most recent call last):
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/cmd/build.py", line 280, in build_main
    app.build(args.force_all, filenames)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/application.py", line 346, in build
    self.builder.build_all()
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/builders/__init__.py", line 259, in build_all
    self.build(None, summary=__('all source files'), method='all')
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/builders/__init__.py", line 310, in build
    updated_docnames = set(self.read())
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/builders/__init__.py", line 417, in read
    self._read_serial(docnames)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/builders/__init__.py", line 438, in _read_serial
    self.read_doc(docname)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/builders/__init__.py", line 478, in read_doc
    doctree = read_doc(self.app, self.env, self.env.doc2path(docname))
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/io.py", line 221, in read_doc
    pub.publish()
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/core.py", line 217, in publish
    self.document = self.reader.read(self.source, self.parser,
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/io.py", line 126, in read
    self.parse()
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/readers/__init__.py", line 77, in parse
    self.parser.parse(self.input, document)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/parsers.py", line 104, in parse
    self.statemachine.run(inputlines, document, inliner=self.inliner)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 170, in run
    results = StateMachineWS.run(self, input_lines, input_offset,
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 241, in run
    context, next_state, result = self.check_line(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 459, in check_line
    return method(match, context, next_state)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2769, in underline
    self.section(title, source, style, lineno - 1, messages)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 327, in section
    self.new_subsection(title, lineno, messages)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 393, in new_subsection
    newabsoffset = self.nested_parse(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 281, in nested_parse
    state_machine.run(block, input_offset, memo=self.memo,
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 196, in run
    results = StateMachineWS.run(self, input_lines, input_offset)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 241, in run
    context, next_state, result = self.check_line(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 459, in check_line
    return method(match, context, next_state)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2769, in underline
    self.section(title, source, style, lineno - 1, messages)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 327, in section
    self.new_subsection(title, lineno, messages)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 393, in new_subsection
    newabsoffset = self.nested_parse(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 281, in nested_parse
    state_machine.run(block, input_offset, memo=self.memo,
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 196, in run
    results = StateMachineWS.run(self, input_lines, input_offset)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 241, in run
    context, next_state, result = self.check_line(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/statemachine.py", line 459, in check_line
    return method(match, context, next_state)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2342, in explicit_markup
    nodelist, blank_finish = self.explicit_construct(match)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2354, in explicit_construct
    return method(self, expmatch)
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2096, in directive
    return self.run_directive(
  File "PATH/.tox/docs/lib/python3.8/site-packages/docutils/parsers/rst/states.py", line 2146, in run_directive
    result = directive_instance.run()
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/directive.py", line 146, in run
    documenter.generate(more_content=self.content)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 957, in generate
    self.document_members(all_members)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 838, in document_members
    documenter.generate(
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 1679, in generate
    return super().generate(more_content=more_content,
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 947, in generate
    self.add_directive_header(sig)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 1579, in add_directive_header
    bases = [restify(cls) for cls in self.object.__orig_bases__]
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/ext/autodoc/__init__.py", line 1579, in <listcomp>
    bases = [restify(cls) for cls in self.object.__orig_bases__]
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/util/typing.py", line 103, in restify
    return _restify_py37(cls)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/util/typing.py", line 142, in _restify_py37
    text += r"\ [%s]" % ", ".join(restify(a) for a in cls.__args__)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/util/typing.py", line 142, in <genexpr>
    text += r"\ [%s]" % ", ".join(restify(a) for a in cls.__args__)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/util/typing.py", line 103, in restify
    return _restify_py37(cls)
  File "PATH/.tox/docs/lib/python3.8/site-packages/sphinx/util/typing.py", line 158, in _restify_py37
    return ':obj:`%s.%s`' % (cls.__module__, cls.__name__)
AttributeError: 'ForwardRef' object has no attribute '__name__'

[tk0miya]

Thank you for reporting. I'll take a look and release a bugfix sooner.

[sobolevn]

Related: https://readthedocs.org/projects/returns/builds/12608226/