Freeing up space · One-tap clean-up (Run Tuhi)
What does the "Clear developer & package caches" step remove?
Short answer: It clears rebuildable build and package-manager caches from tools such as Xcode, Homebrew, npm, pip, cargo and yarn. Projects and settings aren't touched; the next build may just take longer.
It clears build and package-manager caches — the kind of data tools such as Xcode, Homebrew, npm, pip, cargo and yarn download or generate to speed things up and can recreate on demand. Your source code, projects and settings are not touched.
The step only appears in a run when there's a worthwhile amount to clear. The trade-off is time, not data: the next build or package install may take a little longer while the cache refills.
If you'd rather keep a large cache and just get it off your built-in drive, What's Using Space can move it to your fast drive instead. See which developer caches Free Up Space checks.