Nix Installer tries to install to 301 on MacOS Sequoia but fails due to user being there

[Eveeifyeve]

Platform

• macOS Sequoia beta 2

Additional information

Nix tries to install a user on 301 but is taken by _modelmanagerd 301 which might mean apple intelligence is taking user space I had to specify what user id I want nix to install which 400 which works.

Output

I am executing:

    $ sudo /usr/bin/dscl . create /Users/_nixbld1 UniqueID 301

Creating the Nix build user (#1), _nixbld1

<main> attribute status: eDSRecordAlreadyExists
<dscl_cmd> DS Error: -14135 (eDSRecordAlreadyExists)

To get around it

add NIX_FIRST_BUILD_UUID=400 to temporarily fix the issue.
and when uninstalling follow the guide to uninstall the users to fix the _nixbuild1 is a user: https://nix.dev/manual/nix/2.22/installation/uninstall

The solution

So I would say adjust the user id to something like 400-450 or do what @tomberek is implement the automatic uuid assignment for MacOS.

Priorities

#2242
#6153
#10892
https://mastodon.social/@ryanbooker/112597391954278800

Tags

@tomberek

[abathur]

This is already being tracked in the pinned issue you linked:

• macOS 15 Sequoia clobbers _nixbld1-4 users #10892

There's also a draft fix open in:

• install-darwin: fix _nixbld uids for macOS sequoia #10919