Current status of Nix on macOS Catalina?

macOS Catalina was just released today. What’s the current status of Nix on it? I remember a while ago seeing that there were issues with the filesystem changes, did that get resolved?


I found the issue on this

It sounds like this is still an open problem.

I just upgraded to Catalina. The updater deleted the /nix directory.

I’ve just read the long thread about /nix on GitHub (I wish I would have read it before upgrading…).

The updater deleted the /nix directory.

You can find your /nix at /Users/Shared/Relocated Items/Security/nix… now to go read the GitHub thread myself and see about this whole read-only root filesystem thing. :slight_smile:

You can find your /nix at /Users/Shared/Relocated Items/Security/nix


Following the instruction on the GitHub issue, I was able to create an (unencrypted) partition for Nix mounted on a “synthetic” /nix directory. Then I copied the store and var directores from /Users/Shared/Relocated Items/Security/nix to /nix.

Not trivial, but I now have a working Nix installation again.

I’m also back up and running. I listed exactly what I did in this comment. All’s well.

I suspect anything that installs system-wide LaunchDaemons (@LnL7’s nix-darwin?) might have a bit more trouble (see NixOS/nix#3125 for issues with nix-daemon in a multi-user install), but it should be surmountable, and there are reasonable workarounds involving wait4path — basically, the contents of /nix/ aren’t available at boot, so launchd can’t load plists that are just symlinks into the Nix store).

I’ve cobbled together a procedure (from all the useful tips on #2925) that allowed me to have Nix working on first boot after upgrading to Catalina from Mojave with a multi-user Nix setup. Thought it might be helpful to others, so I figured I’d link it here:

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Only half on topic, but how has anyone who has taken the dive on a daily-driver found living with Catalina+Nix (and are you using nix-darwin?) so far? I’ve seen more grousing than usual with Catalina (e.g.: so I’ve been planning to stay on Mojave for a bit.

I did a fresh install of Catalina, but had no problems with nix, nix-darwin or home-manager other than having to setup /nix and /run. Upgrading seems to have fixed a display corruption issue I encountered occasionally and I haven’t encountered any further problems except some apps needed updating for different reasons.


Could you tell me how you setup /nix and /run on a fresh install of Catalina?