3.11.0b1 ValueError "not a valid range"

[AA-Turner]

Sphinx's CI failed on a PR to fix a typo, but only on 3.11.0b1 with a mysterious error:

ImportError while loading conftest '/home/runner/work/sphinx/sphinx/tests/conftest.py'.
ValueError: line 1-0 is not a valid range

CI link (sorry, I tried to install 3.11.0b1 on windows for a smaller reproducer but my computer disagreed) https://github.com/sphinx-doc/sphinx/runs/6669825488?check_suite_focus=true

Packages

distlib-0.3.4 filelock-3.7.0 packaging-21.3 platformdirs-2.5.2 pluggy-1.0.0 py-1.11.0 pyparsing-3.0.9 six-1.16.0 toml-0.10.2 tox-3.25.0 virtualenv-20.14.1 alabaster==0.7.12,attrs==21.4.0,Babel==2.10.1,certifi==2022.5.18.1,charset-normalizer==2.0.12,Cython==0.29.30,docutils==0.18.1,html5lib==1.1,idna==3.3,imagesize==1.3.0,iniconfig==1.1.1,Jinja2==3.1.2,MarkupSafe==2.1.1,packaging==21.3,pluggy==1.0.0,py==1.11.0,Pygments==2.12.0,pyparsing==3.0.9,pytest==7.1.2,pytz==2022.1,requests==2.27.1,six==1.16.0,snowballstemmer==2.2.0,sphinxcontrib-applehelp==1.0.2,sphinxcontrib-devhelp==1.0.2,sphinxcontrib-htmlhelp==2.0.0,sphinxcontrib-jsmath==1.0.1,sphinxcontrib-qthelp==1.0.3,sphinxcontrib-serializinghtml==1.1.5,tomli==2.0.1,urllib3==1.26.9,webencodings==0.5.1

pytest 7.1.2; ubuntu 18.04.6

My guess is this is an issue with pytest (or 3.11.0b1?) as it failed whilst loading conftest, and nothing changed beyond two typos. I searched for "not a valid range" but didn't find any prior issues.

A

[The-Compiler]

Possibly related: python/cpython#92597

(end_lineno is set to 0 instead of a saner value in the AST of Python 3.11)

[nedbat]

Also related: python/cpython#93387

[hroncok]

Test failures of pytest itself:

$ tox -e py311
py311 inst-nodeps: .../pytest/.tox/.tmp/package/1/pytest-7.2.0.dev138+g130c954bb.tar.gz
py311 installed: argcomplete==2.0.0,attrs==21.4.0,certifi==2022.5.18.1,charset-normalizer==2.0.12,elementpath==2.5.3,hypothesis==6.46.9,idna==3.3,iniconfig==1.1.1,mock==4.0.3,nose==1.3.7,packaging==21.3,pluggy==1.0.0,py==1.11.0,Pygments==2.12.0,pyparsing==3.0.9,pytest @ file://.../pytest/.tox/.tmp/package/1/pytest-7.2.0.dev138%2Bg130c954bb.tar.gz,requests==2.27.1,sortedcontainers==2.4.0,urllib3==1.26.9,xmlschema==1.11.1
py311 run-test-pre: PYTHONHASHSEED='3950729182'
py311 run-test: commands[0] | pytest
Traceback (most recent call last):
  File ".../pytest/.tox/py311/bin/pytest", line 8, in <module>
    sys.exit(console_main())
             ^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 188, in console_main
    code = main()
           ^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 146, in main
    config = _prepareconfig(args, plugins)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 327, in _prepareconfig
    config = pluginmanager.hook.pytest_cmdline_parse(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/pluggy/_hooks.py", line 265, in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/pluggy/_manager.py", line 80, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/pluggy/_callers.py", line 55, in _multicall
    gen.send(outcome)
    ^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/helpconfig.py", line 103, in pytest_cmdline_parse
    config: Config = outcome.get_result()
                     ^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/pluggy/_result.py", line 60, in get_result
    raise ex[1].with_traceback(ex[2])
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/pluggy/_callers.py", line 39, in _multicall
    res = hook_impl.function(*args)
          ^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 1032, in pytest_cmdline_parse
    self.parse(args)
    ^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 1320, in parse
    self._preparse(args, addopts=addopts)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 1199, in _preparse
    self.pluginmanager.consider_preparse(args, exclude_only=False)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 677, in consider_preparse
    self.consider_pluginarg(parg)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 703, in consider_pluginarg
    self.import_plugin(arg, consider_entry_points=True)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 759, in import_plugin
    self.register(mod, modname)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 473, in register
    self.consider_module(plugin)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 715, in consider_module
    self._import_plugin_specs(getattr(mod, "pytest_plugins", []))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 722, in _import_plugin_specs
    self.import_plugin(import_spec)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/config/__init__.py", line 749, in import_plugin
    __import__(importspec)
    ^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1178, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1149, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/assertion/rewrite.py", line 159, in exec_module
    source_stat, co = _rewrite_test(fn, self.config)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../pytest/.tox/py311/lib/python3.11/site-packages/_pytest/assertion/rewrite.py", line 361, in _rewrite_test
    co = compile(tree, strfn, "exec", dont_inherit=True)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: line 6-0 is not a valid range
ERROR: InvocationError for command .../pytest/.tox/py311/bin/pytest (exited with code 1)
___________________________________ summary ____________________________________
ERROR:   py311: commands failed

[nedbat]

This is fixed by python/cpython#93359 most likely.

[jeanas]

As helpfully pointed out by @pablogsal on python-dev (https://mail.python.org/archives/list/python-dev@python.org/thread/VZ222BFFAWW73DYFCR7NZR2C5M3TXD65/), you can work around this issue by invoking pytest with --assert=plain.

[hroncok]

This is fixed by python/cpython#93359 most likely.

I can confirm that this is indeed fixed by that commit.

[nicoddemus]

Thanks @hroncok!

I suppose we can close this then?

[chmp]

Since I'm using the private pytest API, I only have to myself to blame, but just an FYI: the missing end_lineno values are creating issues when running pytest inside notebooks using ipytest (maintained by me).

As a fix I will set the end_lineno of the top-level import statements (see here). The reason why the issue persists in IPython is, that IPython explicitly calls ast.fix_missing_locations which creates an invalid line range (see here).