MacOS Catalina: Slow by Design?

Up until the release of Catalina, I've always upgraded to the latest version of macOS within a month or two. But some of the changes this time is really stopping me from upgrading.

As of Catalina, there's no sane way to install the Nix package manager without losing functionality because macOS now disallows creating new files in the root directory[1]. Nix stores its packages in the /nix directory and it's not possible to migrate without causing major disruptions for existing NixOS and other Linux users. This is too bad, since apart from Nix being a nice package manager, it also provides a sane binary package for Emacs. The Homebrew core/cask versions only provides a limited feature set[2][3].

[1]: https://github.com/NixOS/nix/issues/2925

[2]: https://github.com/Homebrew/homebrew-core/issues/31510

[3]: https://github.com/caldwell/build-emacs/search?q=support+is%...

IMHO the original choice of the path seems incredibly ill-advised and the main burden lies with the original developers.

sometimes old errors and mistakes come back and bite

It only seems that way now because some platforms have begun locking down their root directories. Nix, by design, doesn't conform to the FHS way of organizing directories so it made perfect sense to use /nix when the decision was originally made.

> Nix, by design, doesn't conform to the FHS way of organizing directories so it made perfect sense to use /nix when the decision was originally made.

Refusing to conform to the FHS doesn't mean their decision made sense; refusing to conform to the FHS means they made a bad decision in the past and everything progressed from there.

It doesn't 'seem that way now because some platforms have begun locking down their root directories'; it seems that way because creating arbitrary directories in / is a terrible idea, and has been at least since I started using UNIX/Linux systems in the 90's.

Fact is, they made a bad design choice, and now it's come back to bite them (and their users) in the ass.

> creating arbitrary directories in / is a terrible idea, and has been at least since I started using UNIX/Linux systems in the 90's

Why?

Because the root directory might be on a very small partition (perhaps only a few hundred megabytes), while other mount points like /usr might have more space; the only things which should be in / are the things which are necessary to mount the other filesystems (perhaps through the network using NFS).

(Yes, nowadays hard disks are much larger, we have things like initrd, and we now make /bin and /sbin symlinks to within /usr, but the parent comment did mention the 90s...)