What is the iPad-ification? Just the code signing stuff? I guess you can't write to /System anymore these days? And there's something about app notarization, but it doesn't really affect any of my uses.
What's left is a few major runtimes (OpenJDK, golang is waiting for 1.16 to be released). Many of the packages that are not properly supported either require golang [4], rust [2], mono [3] or java to support arm64.
It's impressive the amount of work Apple has done behind the scenes get M1 support in many open source packages, [1] for example.
[0] https://github.com/Homebrew/brew/issues/7857
[1] https://github.com/Unity-Technologies/mono/commit/3f2278e081484e6616ee5892895f999610453ca9
[2] https://github.com/rust-lang/rust/issues/73908
[3] https://github.com/mono/mono/pull/20014
[4] https://github.com/golang/go/issues/38485The way you've substituted "BSD" for macOS really doesn't make sense. Yes, there is BSD code in MacOS, quite a bit of it in fact. But they're not the same thing.
For 99% of other things that run in a terminal, you can get it to work in FreeBSD/macOS. Also, for Python folks, there is anaconda distribution that is agnostic to the underlying OS. Ditto for node or ruby development. Also Gui Emacs and vi have decent ports to macOS.
That said, I guess if you are doing some custom server side development that really needs Linux, you will have a hard time with M1 - virtualization and emulation don’t mix and your code might not be portable enough.
Personally, I have very frequently had the experience that Unixy stuff that "just works" on *BSD or Linux does not work on Mac straight away, or breaks with a new OS release, etc. It takes effort for the homebrew folks or the macports folks or whatever to keep stuff working.
Note: You can’t copy passwords stored in your Local Items or iCloud Keychain. To transfer these keychain items to another computer, set up iCloud Keychain on the other computer using your iCloud user name (normally your Apple ID) and password. You can manually copy keychains other than Local Items or iCloud Keychains to another Mac using the steps below.
https://support.apple.com/guide/keychain-access/copy-keychai...
Either way, I'm not sure this counts as a warning! It rather reminds me of:
As you are probably aware, plans for the development of the outlying regions of the galaxy invoke the building of a hyperspace express route through your star system. And your planet is one of those scheduled for demolition.
(Shouts of terror emit around the globe.)
There's no point acting all surprised about it; the plans and demolition orders have been on display at your local planning department in Alpha Centauri for fifty of your earth years. If you can't be bothered to take an interest in local affairs, that's your own lookout.
Most people setting up their keychain without iCloud will never see this, and there's not even an explicit mention here of the issue with backups (though one could sort of infer that).