OP here, thanks for clarifying this - I can imagine it's a super complex problem and I truly appreciate all the work that you (and other contributors) have put into this project.

My only point (and a source of confusion) here is that I never anticipated the cascading effect that installing a single package can have on seemingly unrelated parts of the system. I've been using homebrew for many years and as far as I remember, the only time anything broke like this was when I explicitly ran update/upgrade.

I'm going to try HOMEBREW_NO_INSTALL_UPGRADE/HOMEBREW_NO_AUTO_UPDATE — it does seem like a more intuitive default, but again, I don't know anything about how homebrew works under the hood.

Thanks again!