Installation failure

Last login: Thu Sep 14 23:40:39 on console
mk9y@Mac-mini ~ % curl -L https://nixos.org/nix/install | sh
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downloading Nix 2.17.0 binary tarball for aarch64-darwin from 'https://releases.nixos.org/nix/nix-2.17.0/nix-2.17.0-aarch64-darwin.tar.xz' to '/var/folders/tl/lw9x165j14n1vqtkbgkwf6wc0000gt/T/nix-binary-tarball-unpack.XXXXXXXXXX.ylnw0aY6'...
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Switching to the Multi-user Installer
Welcome to the Multi-User Nix Installation

This installation tool will set up your computer with the Nix package
manager. This will happen in a few stages:

1. Make sure your computer doesn't already have Nix. If it does, I
   will show you instructions on how to clean up your old install.

2. Show you what I am going to install and where. Then I will ask
   if you are ready to continue.

3. Create the system users (uids [301..332]) and groups (gid 30000)
   that the Nix daemon uses to run builds.

4. Perform the basic installation of the Nix files daemon.

5. Configure your shell to import special Nix Profile files, so you
   can use Nix.

6. Start the Nix daemon.

Would you like to see a more detailed list of what I will do?
No TTY, assuming you would say yes :)

I will:

 - make sure your computer doesn't already have Nix files
   (if it does, I will tell you how to clean them up.)
 - create local users (see the list above for the users I'll make)
 - create a local group (nixbld)
 - install Nix in to /nix
 - create a configuration file in /etc/nix
 - set up the "default profile" by creating some Nix-related files in
   /var/root
 - back up /etc/bashrc to /etc/bashrc.backup-before-nix
 - update /etc/bashrc to include some Nix configuration
 - back up /etc/zshrc to /etc/zshrc.backup-before-nix
 - update /etc/zshrc to include some Nix configuration
 - create a Nix volume and a LaunchDaemon to mount it
 - create a LaunchDaemon (at /Library/LaunchDaemons/org.nixos.nix-daemon.plist) for nix-daemon

Ready to continue?
No TTY, assuming you would say yes :)

---- let's talk about sudo -----------------------------------------------------
This script is going to call sudo a lot. Normally, it would show you
exactly what commands it is running and why. However, the script is
run in a headless fashion, like this:

  $ curl -L https://nixos.org/nix/install | sh

or maybe in a CI pipeline. Because of that, I'm going to skip the
verbose output in the interest of brevity.

If you would like to
see the output, try like this:

  $ curl -L -o install-nix https://nixos.org/nix/install
  $ sh ./install-nix


~~> Fixing any leftover Nix volume state
Before I try to install, I'll check for any existing Nix volume config
and ask for your permission to remove it (so that the installer can
start fresh). I'll also ask for permission to fix any issues I spot.

~~> Checking for artifacts of previous installs
Before I try to install, I'll check for signs Nix already is or has
been installed on this system.

---- Nix config report ---------------------------------------------------------
        Temp Dir:	/var/folders/tl/lw9x165j14n1vqtkbgkwf6wc0000gt/T/tmp.qsOXwp40
        Nix Root:	/nix
     Build Users:	32
  Build Group ID:	30000
Build Group Name:	nixbld

build users:
    Username:	UID
     _nixbld1:	301
     _nixbld2:	302
     _nixbld3:	303
     _nixbld4:	304
     _nixbld5:	305
     _nixbld6:	306
     _nixbld7:	307
     _nixbld8:	308
     _nixbld9:	309
     _nixbld10:	310
     _nixbld11:	311
     _nixbld12:	312
     _nixbld13:	313
     _nixbld14:	314
     _nixbld15:	315
     _nixbld16:	316
     _nixbld17:	317
     _nixbld18:	318
     _nixbld19:	319
     _nixbld20:	320
     _nixbld21:	321
     _nixbld22:	322
     _nixbld23:	323
     _nixbld24:	324
     _nixbld25:	325
     _nixbld26:	326
     _nixbld27:	327
     _nixbld28:	328
     _nixbld29:	329
     _nixbld30:	330
     _nixbld31:	331
     _nixbld32:	332

Ready to continue?
No TTY, assuming you would say yes :)

---- Preparing a Nix volume ----------------------------------------------------
    Nix traditionally stores its data in the root directory /nix, but
    macOS now (starting in 10.15 Catalina) has a read-only root directory.
    To support Nix, I will create a volume and configure macOS to mount it
    at /nix.

~~> Configuring /etc/synthetic.conf to make a mount-point at /nix
Password:

~~> Creating a Nix volume
disk3s7 was already unmounted

~~> Configuring /etc/fstab to specify volume mount options

~~> Configuring LaunchDaemon to mount 'Nix Store'

~~> Setting up the build group nixbld
            Created:	Yes

~~> Setting up the build user _nixbld1
<main> attribute status: eDSRecordAlreadyExists
<dscl_cmd> DS Error: -14135 (eDSRecordAlreadyExists)

---- oh no! --------------------------------------------------------------------
Oh no, something went wrong. If you can take all the output and open
an issue, we'd love to fix the problem so nobody else has this issue.

:(

We'd love to help if you need it.

You can open an issue at
https://github.com/NixOS/nix/issues/new?labels=installer&template=installer.md

Or get in touch with the community: https://nixos.org/community
mk9y@Mac-mini ~ % 

It looks like you had some remaining artifacts of an earlier install. I’d follow Uninstalling Nix - Nix Reference Manual and then try again.

I uninstalled, and failed to install, again with same message.

Ah, sorry. I guess the conflict is probably the UID and not the username.

It looks like most people who’ve run into this on macOS have a SonosDMS user already at UID 301. Some people were no longer using Sonos, so they just removed that user and tried again.

If you’re still using it, the steps in this comment may help: