AttributeError: 'Sphinx' object has no attribute 'add_description_unit' (pytest pytest-4.3.1.dev110+g51bf7c3a, sphinx 2.0.0b1)

[hroncok]

Describe the bug
pytest documentation cannot be built.

See pytest-dev/pytest#4912

To Reproduce

[tmp]$ git clone https://github.com/pytest-dev/pytest.git
...
[tmp]$ cd pytest
[tmp]$ git rev-parse HEAD
51bf7c3aef8f018f44e7c36378be894aa13e32b5
[pytest (master)]$ python3.7 -m venv __venv__
[pytest (master)]$ . __venv__/bin/activate
(__venv__) [pytest (master)]$ pip install --pre sphinx
...
Successfully installed Jinja2-2.10 MarkupSafe-1.1.1 Pygments-2.3.1 alabaster-0.7.12 babel-2.6.0 certifi-2019.3.9 chardet-3.0.4 docutils-0.14 idna-2.8 imagesize-1.1.0 packaging-19.0 pyparsing-2.3.1 pytz-2018.9 requests-2.21.0 six-1.12.0 snowballstemmer-1.2.1 sphinx-2.0.0b1 sphinxcontrib-applehelp-1.0.1 sphinxcontrib-devhelp-1.0.1 sphinxcontrib-htmlhelp-1.0.1 sphinxcontrib-jsmath-1.0.1 sphinxcontrib-qthelp-1.0.2 sphinxcontrib-serializinghtml-1.1.1 urllib3-1.24.1
(__venv__) [pytest (master)]$ cd doc/en
(__venv__) [en (master)]$ pip install -r requirements.txt
...
Successfully installed pygments-pytest-1.2.0 sphinx-removed-in-0.1.3 sphinxcontrib-trio-1.0.2
(__venv__) [en (master)]$ pip install ../..
...
Successfully installed atomicwrites-1.3.0 attrs-19.1.0 more-itertools-6.0.0 pluggy-0.9.0 py-1.8.0 pytest-4.3.1.dev110+g51bf7c3a
(__venv__) [en (master)]$ sphinx-build -W -b html . _build
Running Sphinx v2.0.0b1
making output directory... done

Exception occurred:
  File "/home/churchyard/tmp/pytest/doc/en/conf.py", line 338, in setup
    app.add_description_unit(
AttributeError: 'Sphinx' object has no attribute 'add_description_unit'
The full traceback has been saved in /tmp/sphinx-err-k3n0s9df.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!
(__venv__) [en (master)]$ cat /tmp/sphinx-err-k3n0s9df.log
# Sphinx version: 2.0.0b1
# Python version: 3.7.2 (CPython)
# Docutils version: 0.14 
# Jinja2 version: 2.10
# Last messages:

# Loaded extensions:
Traceback (most recent call last):
  File "/home/churchyard/tmp/pytest/__venv__/lib64/python3.7/site-packages/sphinx/cmd/build.py", line 283, in build_main
    args.tags, args.verbosity, args.jobs, args.keep_going)
  File "/home/churchyard/tmp/pytest/__venv__/lib64/python3.7/site-packages/sphinx/application.py", line 242, in __init__
    self.config.setup(self)
  File "/home/churchyard/tmp/pytest/doc/en/conf.py", line 338, in setup
    app.add_description_unit(
AttributeError: 'Sphinx' object has no attribute 'add_description_unit'

Expected behavior
Build the docs.

Your project
https://github.com/pytest-dev/pytest

Environment info

• OS: Linux (Fedora 29 to 31)
• Python version: 3.7.2
• Sphinx version: 2.0.0b1
• Sphinx extensions: default

[hroncok]

This was apparently deprecated. Sorry about the noise.

[hroncok]

Actually, this is still documented:

sphinx/sphinx/application.py

Lines 830 to 831 in 8d0d75f

	This method is also available under the deprecated alias
	:meth:`add_description_unit`.

[hroncok]

Should this sentence be removed from the docstring?

[tk0miya]

Oh, yes. You're right. It should be removed.

[tk0miya]

Closing this now.
Thank you for reporting :-)