python runtime_error ai_generated true

pytest.fail() called without a message; use pytest.fail(reason='...')

ID: python/pytest-fail-without-message

Also available as: JSON · Markdown · 中文
80%Fix Rate
86%Confidence
0Evidence
2026-09-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.10 active — — —

Root Cause

Calling pytest.fail() without a reason argument is deprecated or raises an error in newer pytest versions to enforce descriptive failure messages.

generic

中文

在较新的 pytest 版本中，调用 pytest.fail() 而不提供 reason 参数已被弃用或引发错误，以强制提供描述性的失败消息。

Workarounds

  1. 95% success 
    Always provide a reason: pytest.fail(reason='Expected condition not met')
  2. 90% success 
    Use pytest.fail('message') as a positional argument, which is equivalent to pytest.fail(reason='message').

Dead Ends

Common approaches that don't work:

  1. 50% fail

    Using a bare raise or assert False may work but loses the structured failure reporting of pytest.

  2. 60% fail

    Ignoring the warning and continuing to use pytest.fail() without argument may cause test failures in future pytest versions.