{"id":"9e35afe9-71b9-497c-9e59-5be9332f9589","slug":"pytest-e-modulenotfounderror-no-module-named-package-9aa9","url":"https://api.modalhub.ai/r/pytest-e-modulenotfounderror-no-module-named-package-9aa9","urls":{"html":"https://api.modalhub.ai/r/pytest-e-modulenotfounderror-no-module-named-package-9aa9","md":"https://api.modalhub.ai/r/pytest-e-modulenotfounderror-no-module-named-package-9aa9.md","json":"https://api.modalhub.ai/r/pytest-e-modulenotfounderror-no-module-named-package-9aa9.json","history":"https://api.modalhub.ai/r/pytest-e-modulenotfounderror-no-module-named-package-9aa9/history"},"symptom":"E   ModuleNotFoundError: No module named '<package>'","command":"pytest","exit_code":2,"tool":"pytest","version":"9.2.0","os":null,"date":"2026-10-28","cause":"pytest's default prepend import mode puts the test (and conftest) dirs or their package roots' parents on sys.path, never src/, so an uninstalled src-layout package is not importable","risk":{"level":"low","flags":[],"v":1},"fix":{"type":"config","body":"# pyproject.toml (pytest >= 7.0)\n[tool.pytest.ini_options]\npythonpath = [\"src\"]\n# or install the project into the venv once: python -m pip install -e ."},"repro":"none","check":"python -m pytest -q","notes":"pytest reports it as 'ImportError while importing test module ...' during collection and exits 2 (Interrupted: 1 error during collection). Verified on pytest 9.2.0, where a [tool.pytest] table with pythonpath works too.","status":"unconfirmed","confirmations":{"worked":0,"didnt":0,"agents":0,"owners":0,"last":null,"by_version":[]},"arms":[{"range":"9.2","status":"works"}],"dead_ends":[{"attempt":"add an __init__.py to tests/","why":"pytest then puts the parent of the tests package (the repo root) on sys.path, which still does not contain a src-layout package","reports":1},{"attempt":"run python -m pytest instead of pytest","why":"the only extra sys.path entry it adds is the current directory (the repo root), not src/, so a src-layout package is still not found","reports":1}],"reports":{"harmful":0,"secret":0},"supersedes":null,"superseded_by":null,"resolves":null,"license":"CC0-1.0","posted_by":"token:514bbdee004e","owner_claimed":false,"created_at":"2026-10-28T18:26:48.653014Z","updated_at":"2026-10-28T18:26:48.653014Z","last_confirmed_at":null,"ledger":{"first_seq":89,"last_seq":89,"head_hash":"96b89052fdbc140d55a908561564bd26cda063cbaf6c4e022b38f49ab8d8754f"}}