bug: Setting Fish/Nushell as Default Shell Breaks Home Manager Modules on macOS

[phucleeuwu]

Are you following the right branch?

• My Nixpkgs and Home Manager versions are in sync

Is there an existing issue for this?

• I have searched the existing issues

Issue description

Description

I use shell integration for every module. When I set Fish or Nushell as my default shell on macOS, Home Manager modules (such as atuin, eza, fzf, ... ) none of them are work or recognized. However, if I use macOS's default shell (zsh) and then manually start fish or nu, everything works fine.

Steps to Reproduce

1. Ensure Fish or Nushell is installed via Home Manager.
2. Add Fish or Nushell to /etc/shells.
3. Change the default shell:

   chsh -s 

4. Restart the terminal and open a new session.
5. Try running commands from installed Home Manager modules (e.g., atuin, eza).

Expected Behavior

Fish or Nushell should correctly recognize commands installed by Home Manager.

Actual Behavior

Commands such as atuin, eza, and fzf are not found, leading to errors like:

fish: Unknown command: atuin
- (line 1):
atuin uuid
^~~~^
...
fish: Unknown command: eza
- (line 1):
function eza --description 'alias eza eza --icons always --color always --git --group-directories-first'; command eza --icons always --color always --git --group-directories-first $argv

Additional Information

• OS: macOS
• Shells Affected: Fish, Nushell
• Works in: Zsh (when launching Fish/Nushell manually)
• Fails in: Fish/Nushell (when set as the default shell)
• Nix Setup: Nix-Darwin Flake (Unstable) + Home Manager (Unstable)

Possible Cause

Home Manager environment variables and paths may not be properly initialized when Fish/Nushell is set as the default shell.

Would appreciate any insights on how to fix this issue! Thanks!

Maintainer CC

@trueNAHO @rycee

System information

- system: `"aarch64-darwin"`
 - host os: `Darwin 24.3.0, macOS 15.3.1`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.24.12`
 - nixpkgs: `/nix/store/xfh1w1c6d3v1b79fwdfnddcbg1pdj674-source`