Error during watch: Too many open files (macOS)

[fasterthanlime]

When running attic watch-store main on my macOS machine, it's stuck for a minute, and then it spams:

Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }
Error during watch: Error { kind: Io(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), paths: [] }

..while not actually pushing anything.

The same version of attic works fine on a (remote) Linux machine.

[dbaynard]

I'm not an attic user (yet) but I hit similar issues with nix a while ago — I was trying to build a nix-darwin system.

> launchctl limit maxfiles
        maxfiles    256            unlimited

> ulimit -n
256

I think setting this helped — I was able to complete the build, having set it, but I haven't confirmed it was the direct fix.

ulimit -n 10240

Hopefully this may help someone affected by the issue.

Some resources:

• increase max file descriptors on darwin by default · Issue #173657 · NixOS/nixpkgs
• Too many open files error on Mac OS: ulimit -n 10240 works, higher n values don't — Apple Community
• launchd: Set NumberOfFiles to 4096 by azuwis · Pull Request #5726 · NixOS/nix

[kradalby]

I'm running into this on macOS aswell, I've set ulimit to max, which is 65536 it seems, and sadly still running into it. I'm unsure if there is any good fix available if your Nix store is too big...