fable-compiler/fable: technical due diligence, read from its repository

The median source file here is 175 lines. 57 files exceed 1,750 lines, the largest being 12,984. 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.

Of five ordinary markers — CI workflows, CODEOWNERS, a pull-request template, pre-commit hooks, contribution guidance — 1 is present: CI workflows. Branch protection itself is a GitHub setting rather than a file, so this is a reading of proxies and not of the rules themselves. What it does establish is that the process is not written down anywhere a new engineer would find it.

10 third-party CI actions are referenced by a tag or branch rather than a commit, so they run whatever that tag points to on the day. 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.

2 of 209 locked dependencies match 4 published advisories in OSV, 3 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: only the build reaches them: a bundler, a code generator, a build plugin, or a lockfile in a tooling directory.

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.