python runtime_error ai_generated true

AttributeError: 'MonkeyPatch' object has no attribute 'undo'

ID: python/pytest-monkeypatch-undo

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80%Fix Rate
86%Confidence
0Evidence
2025-10-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.0.0 active — — —
8.0.0 active — — —

Root Cause

The monkeypatch fixture's undo method was removed in pytest 6.0+, but older code may still try to call it. The correct way to undo patches is to use context managers or let the fixture automatically revert.

generic

中文

monkeypatch fixture的undo方法在pytest 6.0+中被移除，但旧代码可能仍尝试调用它。正确的撤销补丁方法是使用上下文管理器或让fixture自动恢复。

Workarounds

  1. 95% success Remove calls to monkeypatch.undo() and let the fixture revert changes automatically 
    def test_example(monkeypatch):
    monkeypatch.setattr('os.getcwd', lambda: '/tmp')
    # No need to call undo; fixture reverts on teardown
  2. 90% success Use monkeypatch as a context manager for explicit control 
    with monkeypatch.context() as m:
    m.setattr('os.getcwd', lambda: '/tmp')
    # Changes are reverted after the with block

Dead Ends

Common approaches that don't work:

  1. Downgrading pytest to version 5.x to restore the undo method 60% fail

    This is a temporary fix and prevents using newer pytest features.

  2. Creating a custom undo function manually 40% fail

    This duplicates functionality that already exists in the fixture's automatic teardown.