Hello! I seem to have an issue where unpredictably, my lix / nix-darwin config is "unlinked"?
Opening a terminal I get: /run/current-system/sw/bin/zsh: No such file or directory
Opening forcibly /bin/zsh I get a shell. I see nix is still in the path. I attempt to apply my nix-darwin config and i get:

error: could not connect to any lix socket (tried /nix/var/nix/daemon-socket/socket)

At this point nix doctor returns:

[PASS] PATH contains only one nix version.
[PASS] All profiles are gcroots.
error: could not connect to any lix socket (tried /nix/var/nix/daemon-socket/socket)

I am now entirely out of my depth :), the last time this happened, i uninstalled and reinstalled lix with the installer, applied my config, and I was back as normal. This time, however, I would like to understand what is going on, now that I have the system in this state.

Does anyone know what might be causing this?

More technical details narrowed down. (Apologies, this is AI-guided)

Symptoms:

/run/current-system/sw/bin/zsh: No such file or directory

/nix is mounted:

/dev/disk3s7 on /nix (apfs, local, nosuid, journaled, noatime, nobrowse, protect)

The nix-darwin profile exists and looks sane:

/nix/var/nix/profiles/system -> system-40-link
/nix/var/nix/profiles/system-40-link -> /nix/store/407zf3x5z49cvk7s6s8da1s5i8dp8nm3-darwin-system-26.05.56c666e

but /run/current-system is missing entirely:

$ ls -l /run/current-system
ls: /run/current-system: No such file or directory

Lix/Nix commands that require the daemon fail:

error: could not connect to any lix socket (tried /nix/var/nix/daemon-socket/socket)

nix doctor reports:

[PASS] PATH contains only one nix version.
[PASS] All profiles are gcroots.
error: could not connect to any lix socket (tried /nix/var/nix/daemon-socket/socket)

Launchd state is odd. These are enabled in the override DB:

"org.nixos.nix-daemon" => enabled
"org.nixos.activate-system" => enabled

but they are not loaded:

$ sudo launchctl print system/org.nixos.nix-daemon
Bad request.
Could not find service "org.nixos.nix-daemon" in domain for system

$ sudo launchctl print system/org.nixos.activate-system
Bad request.
Could not find service "org.nixos.activate-system" in domain for system

The plists exist:

-r--r--r--  1 root  wheel   513 May 25 17:57 org.nixos.activate-system.plist
-r--r--r--  1 root  nixbld  910 May 25 17:57 org.nixos.nix-daemon.plist

The plist itself is valid and points to an existing store path:

ProgramArguments = (
  "/bin/sh",
  "-c",
  "/bin/wait4path /nix/store && exec /nix/store/1ynb4idx8g87xpc0c69c23qngx70cdhn-lix-2.94.2/bin/nix-daemon"
)

and that path exists:

/nix/store/1ynb4idx8g87xpc0c69c23qngx70cdhn-lix-2.94.2/bin/nix-daemon -> nix

The most interesting log entry:

2026-06-03 14:38:03.994 launchd[1] [system:] removing active service: org.nixos.nix-daemon

The current nix-darwin activation script contains the expected reload logic:

launchctl unload '/Library/LaunchDaemons/org.nixos.nix-daemon.plist' || true
cp -f '.../org.nixos.nix-daemon.plist' '/Library/LaunchDaemons/org.nixos.nix-daemon.plist'
launchctl load -w '/Library/LaunchDaemons/org.nixos.nix-daemon.plist'

At some point earlier today I did a nix-darwin switch. I also did a minor software update. As far as I can remember, my shell, etc. was working after this. I do not know if the symptoms could be delayed.

Now trying to reinstall lix:

Proceed? ([Y]es/[n]o/[e]xplain): y
 INFO Step: Create an encrypted APFS volume `Nix Store` for Nix on `disk3` and add it to `/etc/fstab` mounting on `/nix`
 INFO Step: Provision Nix
 INFO Step: Create build users (UID 351-382) and group (GID 350)
 INFO Step: Configure Time Machine exclusions
 INFO Step: Configure Nix
 INFO Step: Configuring zsh to support using Nix in non-interactive shells
 INFO Step: Create a `launchctl` plist to put Nix into your PATH
 INFO Step: Configure Nix daemon related settings with launchctl
ERROR 
   0: \x1b[91mInstall failure\x1b[0m
   1: \x1b[91mError executing action\x1b[0m
   2: \x1b[91mAction `configure_init_service` errored\x1b[0m
   3: \x1b[91mFailed to execute command `"launchctl" "bootstrap" "system" "/Library/LaunchDaemons/org.nixos.nix-daemon.plist"`
      stdout: 
      stderr: Bootstrap failed: 5: Input/output error

      exited with status code: 5
      \x1b[0m

Location:
   \x1b[35msrc/cli/subcommand/install/mod.rs\x1b[0m:\x1b[35m287\x1b[0m

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

Consider reporting this error using this URL: https://git.lix.systems/lix-project/lix-installer/issues/new?title=%3Cautogenerated-issue%3E&body=%23%23+Error%0A%60%60%60%0AError%3A+%0A+++0%3A+Install+failure%0A+++1%3A+Error+executing+action%0A+++2%3A+Action+%60configure_init_service%60+errored%0A+++3%3A+Failed+to+execute+command+%60%22launchctl%22+%22bootstrap%22+%22system%22+%22%2FLibrary%2FLaunchDaemons%2Forg.nixos.nix-daemon.plist%22%60%0A++++++stdout%3A+%0A++++++stderr%3A+Bootstrap+failed%3A+5%3A+Input%2Foutput+error%0A%0A++++++exited+with+status+code%3A+5%0A%0A%60%60%60%0A%0A%23%23+Metadata%0A%7Ckey%7Cvalue%7C%0A%7C--%7C--%7C%0A%7C**version**%7C3.95.0%7C%0A%7C**os**%7Cmacos%7C%0A%7C**arch**%7Caarch64%7C%0A
Installation failure, offering to revert...
Lix uninstall plan (v3.95.0)