python system_error ai_generated partial

OSError: [Errno 28] No space left on device: '/tmp/pytest-of-runner/pytest-123/test_x0/data.bin'

ID: python/pytest-tmp-path-not-cleaned

Also available as: JSON · Markdown · 中文
80%Fix Rate
82%Confidence
0Evidence
2025-03-25First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.x active — — —
8.x active — — —

Root Cause

Tests write large files into tmp_path, and pytest's tmp_path retention (default 3 runs) plus parallel xdist workers accumulate data faster than it is pruned.

generic

中文

测试向 tmp_path 写入大文件，加上 pytest 的 tmp_path 保留策略（默认保留 3 次运行）和并行 xdist worker，数据累积速度快于清理速度。

Workarounds

  1. 90% success 
    # pyproject.toml
[tool.pytest.ini_options]
# pytest keeps last 3 by default; use a fixture to clean large files
def test_big(tmp_path):
    p = tmp_path / 'data.bin'
    try:
        p.write_bytes(b'x' * 10_000_000)
        ...
    finally:
        p.unlink(missing_ok=True)
  2. 88% success 
    # CI step
pytest --basetemp=/tmp/pytest-$CI_JOB_ID tests/
rm -rf /tmp/pytest-$CI_JOB_ID

# Or in conftest:
import shutil, pytest
@pytest.fixture(scope='session', autouse=True)
def _clean_basetemp(request):
    yield
    shutil.rmtree(request.config.option.basetemp, ignore_errors=True)

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Buying time, not fixing the leak; suites that grow will hit the same limit and the cost increases.

  2. 85% fail

    RAM disk is smaller than /tmp; large test artifacts fill it faster and cause OOM or ENOSPC sooner.