pytest-dev/pytest · error · TypeError

help argument cannot be None for

Error message

help argument cannot be None for {name}

What it means

helpconfig.py:203 raises TypeError('help argument cannot be None for {name}') when iterating _inidict during 'pytest --help'/'--version'-style ini option rendering and an ini option was registered with help=None. Every ini option registered via parser.addini must supply a non-None help string so the help output can format it.

Solutions

1. Find every addini/register call for the named option and provide a non-None help string.
2. If the option is from a third-party plugin, upgrade it or open an issue; pin pytest if a regression.
3. Audit conftest.py for pytest_addoption/addini calls missing help.

Example fix

// before
parser.addini('my_flag', default=False, type='bool')
// after
parser.addini('my_flag', help='enable my custom behavior', default=False, type='bool')

# In pytest_addoption, validate help is not None
def addini_checked(parser, name, help, **kw):
    assert help is not None, f'help required for ini option {name!r}'
    parser.addini(name, help=help, **kw)

When it happens

Trigger: A plugin/conftest calling config.addini('myopt', help=None, ...); an extension registering a custom ini key without a description string; then the user runs 'pytest --help' or 'pytest -p <plugin>'.

Common situations: Plugin authors forgetting the help argument; copy-pasting addini calls and dropping the help text; upgrading pytest which tightened this validation.

Related errors

• unknown configuration type
• ' ' is not recognized as a logging level name for ' '…
• unknown configuration value
• alias conflicts with existing configuration option
• is already an alias of

AI-assisted analysis of pytest-dev/pytest@0d6fbdeffa (2026-08-11). Data as JSON: /api/errors/f03b17a0ba21d2a1. Report an issue: GitHub.

Appendix: source

Thrown at src/_pytest/helpconfig.py:203

        "terminalreporter"
    )
    assert reporter is not None
    tw = reporter._tw
    tw.write(config._parser.optparser.format_help())
    tw.line()
    tw.line(
        "[pytest] configuration options in the first "
        "pytest.toml|pytest.ini|tox.ini|setup.cfg|pyproject.toml file found:"
    )
    tw.line()

    columns = tw.fullwidth  # costly call
    indent_len = 24  # based on argparse's max_help_position=24
    indent = " " * indent_len
    for name in config._parser._inidict:
        help, type, _default = config._parser._inidict[name]
        if help is None:
            raise TypeError(f"help argument cannot be None for {name}")
        spec = f"{name} ({_ini_type_repr(type)}):"
        tw.write(f"  {spec}")
        spec_len = len(spec)
        if spec_len > (indent_len - 3):
            # Display help starting at a new line.
            tw.line()
            helplines = textwrap.wrap(
                help,
                columns,
                initial_indent=indent,
                subsequent_indent=indent,
                break_on_hyphens=False,
            )

            for line in helplines:
                tw.line(line)
        else:
            # Display help starting after the spec, following lines indented.

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