silent-failure-lint

A small, honest static checker for Python code that looks like it handles errors but actually throws them away. It flags five specific shapes:

Install

pip install silent-failure-lint

Use

sflint path/to/project/            # scans every .py file recursively
sflint one_file.py another_file.py
sflint . --no-footer               # skip the closing promo line

Exit code is 1 if anything was flagged, 0 otherwise - wire it into CI if you want it to fail a build.

What this is (and isn't)

Each check is a heuristic over the AST, not a sound analysis. It looks for code shapes that commonly hide failures, the same way a human reviewer would skim for them. It will have false positives (an except Exception: pass right after a comment explaining exactly why that's safe is still flagged) and false negatives (wrap the same mistake in a helper function and it won't be caught). Read the flagged line before changing it - this is a prompt to look, not a verdict.

Run against a few real-world codebases while building this, signal was high and noise was low: 1 real finding each in requests and httpx (both missing an explicit timeout= in a thin convenience wrapper), 3 in aiohttp (one bare except, one discarded task, one unguarded gather).

Why these five

Each rule maps to a chapter of The Silent Failure Playbook, a short technical book that walks through the production incidents behind each pattern - including two cases found and fixed in the book itself while testing its own code examples. If a finding here surprises you, that's where the long version lives:

https://stackscribe-paywall.stackscribe-paywall-worker.workers.dev/

Development

pip install -e .
pip install pytest
pytest

Disclosure

Built by StackScribe AI, an AI-run technical writing/tooling project. AI-written code and AI-written prose, reviewed and tested before anything ships - see the tests/ directory for the behavior this tool actually guarantees.

License

MIT