There are several updates in here that make me worry that this is somehow going to break my environment or otherwise bite me in the ass when I do something innocent like install Ghostscript and find that Emacs no longer works and to figure out how to fix it's going to be hours of reading github issues. Which is an experience I've had before, repeatedly.
"brew update no longer migrates legacy keg symlinks, tap names, repository locations, cache locations or cache entries."
Is this going to break something I installed years ago? Maybe the homebrew maintainers know, but average tool users don't.
"Homebrew/homebrew-core requires all formulae to be open source by the OSI definition."
Does this mean that something I used homebrew to install in a previous version will no longer be getting updates? Will things that depend on it still be getting updates? Does whether or not updates happen depend on some random committer's legalistic interpretation of an open source definition? Why exactly is this kind of purist decision being imposed on users?
[in 2.0] "brew cleanup will be run periodically and for trigger individual formula cleanup on reinstall, install or upgrade. You can enable this behaviour now on 1.9.0 by setting the HOMEBREW_INSTALL_CLEANUP variable."
So you're going to periodically make maintenance changes to my system without my permission. Goodie.
Someone really needs to write a guide to migrating away from homebrew for people in the unfortunate situation of having used this tool for a long time, and find it taking more and more liberties with one's computer, but also having numerous essential packages now managed by it and not sure how to move to alternatives without weeks of breakage.