Should M1/ARM-based "brew doctor" be checking files in /usr/local

[jimtut]

I ran brew doctor recently to find and clean some legit problems (unlinked files, uncommitted changes, etc.). I was surprised to see warnings like "Unbrewed dylibs were found in /usr/local/lib", "Unbrewed header files were found in /usr/local/include", etc.

I'm on an M1 Mac, with homebrew properly installed in /opt/homebrew. Why would homebrew care about any of the files in /usr/local? I understand that Intel-based homebrew does use that folder, but I didn't think that ARM-based HB did.

Is this a mistake? Should it be removed, or maybe changed to check in /opt/homebrew instead?

Yes, I know brew doctor says "these warnings are just used to help the Homebrew maintainers", but if the code is checking in the WRONG place, it's either NOT checking in the RIGHT place, or just wasting time.

[carlocab]

That is intentional. brew looks at things in /usr/local even when it's not installed there because /usr/local is in the default search path for many things. This means what is installed there is very relevant for brew doctor.