Diagnose import-hook contention¶

metapathology answers a narrow debugging question:

Which finder handled this import, and did that stop another import hook from running?

It is for Python developers investigating behavior that changes when editable installs, test runners, tracing, runtime type checking, or other import hooks are combined.

pip install metapathology
python -m metapathology your_script.py
python -m metapathology -m pytest tests/

The target runs normally. The report goes to standard error at exit. Metapathology observes and reports; it never supplies a module spec or changes an import result.

Choose the next page¶

• Get started to run a reproduction and save a report.
• Read a report to interpret findings and current-state checks.
• Choose capture when the default evidence is insufficient.
• Start earlier when a finder arrived from a .pth file or frozen bootstrap.
• Configure metapathology for CLI, API, and environment settings.
• Consume JSON for integrations and the schema contract.
• Check limitations before drawing a conclusion from missing evidence.

The library API is intended for environments where the CLI wrapper is impractical. Most users do not need it.