astral-sh/ruff: technical due diligence, read from its repository

The median source file here is 50 lines. 173 files exceed 1,000 lines, the largest being 13,223. Size is not a defect on its own — some problems genuinely live in one place — but these are where merge conflicts, review fatigue and single-owner knowledge concentrate, and they are the first thing that slows an inheriting engineer down.

5 files were marked deprecated over two years ago and still are, the oldest since Jul 2023. A deprecation is a promise to remove. Ask what still depends on these, and whether removing them is scheduled.

1 step pipes a download straight into a shell. Tags have been moved to malicious commits in real supply-chain attacks, and a piped script is whatever the server returns that minute. Pinning to a commit is the fix, and it is small.

6 of 787 locked dependencies match 10 published advisories in OSV, 4 of them rated high or critical. A lockfile says which version is installed, not whether the flawed code is reachable from this product, so each needs a look. Most are fixed by an upgrade, and the advisory names the version. None of the high or critical ones is in what the product ships: they are development dependencies. This lockfile pins development tools alongside what ships and does not say which is which, so some of these may never reach a user.

Third-party code is committed into this repository without any statement of the terms it arrived under. Unknown terms are harder to deal with than inconvenient ones: an awkward licence can be complied with, an absent one cannot. Each of these needs its origin established before the code changes hands.

Nothing in the service initialises an error reporter (Sentry, Rollbar, Bugsnag, Honeybadger or an APM agent). An exception in production reaches a person only if someone is reading the logs, which usually means a customer reports it first.