- We have some Linux-only formulae that don't have bottles.
- Previously, bumping a Linux-only formula that didn't have a bottle
line - eg, `adoptopenjdk` which is `bottle :unneeded` - would fail:
```
Error: inreplace failed
/app/linuxbrew/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/adoptopenjdk.rb:
expected replacement of /^ sha256 ".+" => :x86_64_linux\n/m with "\2"
```
The main class you should look at is the {Formula} class (and classes linked from there). That's the class that's used to create Homebrew formulae (i.e. package descriptions). Assume anything else you stumble upon is private.