New nix-darwin install - "error: file 'darwin' was not found in the Nix search path (add it using $NIX_PATH or -I)"

[victorhooi]

I'm trying to setup Nix on a new macOS machine (running macOS Sequoia 15.3.1), and I'm hitting some PATH errors trying to get nix-darwin to install. (I'm a Nix newbie - previously I was using the starter templates from here, but I figured I wanted to try some of it myself).

Firstly, I installed Nix using the Determinate Nix installer:

victorhooi@MacBook-Pro ~ % curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | \
  sh -s -- install
info: downloading installer https://install.determinate.systems/nix/tag/v0.38.1/nix-installer-aarch64-darwin
 INFO nix-installer v0.38.1
`nix-installer` needs to run as `root`, attempting to escalate now via `sudo`...
 INFO nix-installer v0.38.1
 INFO For a more robust Nix installation, use the Determinate package for macOS: https://dtr.mn/determinate-nix

Install Determinate Nix?

Proceed? ([Y]es/[n]o/[e]xplain): yes
Nix install plan (v0.38.1)
Planner: macos

Configured settings:
* determinate_nix: true

Planned actions:
* Install Determinate Nixd
* Create an encrypted APFS volume `Nix Store` for Nix on `disk3` and add it to `/etc/fstab` mounting on `/nix`
* Extract the bundled Nix (originally from /nix/store/1q9hil0gipfxndz3pq6jg4ggmn0syia8-nix-binary-tarball-2.26.2/nix-2.26.2-aarch64-darwin.tar.xz)
* Create a directory tree in `/nix`
* Synchronize /nix/var ownership
* Move the downloaded Nix into `/nix`
* Synchronize /nix/store ownership
* Create build users (UID 351-382) and group (GID 350)
* Configure Time Machine exclusions
* Setup the default Nix profile
* Place the Nix configuration in `/etc/nix/nix.conf`
* Configure the shell profiles
* Configuring zsh to support using Nix in non-interactive shells
* Create a `launchctl` plist to put Nix into your PATH
* Configure the Determinate Nix daemon
* Remove directory `/nix/temp-install-dir`


Proceed? ([Y]es/[n]o/[e]xplain): yes
 INFO Step: Install Determinate Nixd
 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 the Determinate Nix daemon
 INFO Step: Remove directory `/nix/temp-install-dir`
Nix was installed successfully!
To get started using Nix, open a new shell or run `. /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh`

Then, I created a Nix configuration directly at ~/.config/nix, and created a flake.nix using the nix-darwin template:

victorhooi@MacBook-Pro nix % nix flake init -t nix-darwin/master
wrote: "/Users/victorhooi/.config/nix/flake.nix"

Then I edited the hostname using the snippet from the nix-darwin README:

victorhooi@MacBook-Pro nix % sed -i '' "s/simple/$(scutil --get LocalHostName)/" flake.nix

Finally I ran the nix-darwin install command from the README - this is where it seems to error out around the path:

victorhooi@MacBook-Pro nix % nix run nix-darwin/master#darwin-rebuild -- switch

building the system configuration...
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'darwin' was not found in the Nix search path (add it using $NIX_PATH or -I)

I did try spawning a new shell, but I get the same error:

victorhooi@MacBook-Pro nix % nix run nix-darwin/master#darwin-rebuild -- switch
building the system configuration...
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'darwin' was not found in the Nix search path (add it using $NIX_PATH or -I)

UPDATE:

I'm using the default zsh in macOS (although I'd like to switch to fish shortly - or possibly try out nushell...lol).

This is my current $PATH:

victorhooi@MacBook-Pro nix % echo $PATH
/Users/victorhooi/.bun/bin:/Users/victorhooi/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin

[victorhooi]

Hmm - I think my issue might be this one:

#1330

However, I think the README is a little ambigious (as is the README).

I'm still a bit hazy as to why I should be using /etc/nix-darwin as my Nix flake configuration directory - other sources online mention using ~/.config/nix, and other guides seem to put it in other places. However, is /etc/nix-darwin meant to be the proper place?

[TechAssistance]

Same exact issue here. Set config to ~/.config/nix/flake.nix

When trying to run nix run nix-darwin/master#darwin-rebuild --extra-experimental-features "nix-command flakes" -- switch
I get the same error regarding the path. Although I did not install nix using the installer (yay me seems like uninstalling will suck lol).

[TechAssistance]

Issue resolved by declaring --flake ~/.config/nix/flake.nix in the command per this comment.

I think we will need to update the installation instructions or make some better Quickstart docs as this seems to be something changed form a vast majority of existing external guides.

[Enzime]

I've made a PR to clarify this in the README, please let me know if the wording is clear https://github.com/LnL7/nix-darwin/pull/1368/files

[TechAssistance]

Added a comment / recommendation that we make known the --flake option as many users will want to use the .config/nix location anyways.