bug: program.opam.enableFishIntegration results in error

[bikallem]

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

The following results in error:

programs.opam = {
  enable = true;
  enableFishIntegration = true;
};

gives an error below:

~/.config/fish/config.fish (line 12): $(...) is not supported. In fish, please use '(/nix/store/8asq…)'.
eval "$(/nix/store/8asqgnhs89wzyjvs8p1n5hvxn7lkn9wa-opam-2.1.3/bin/opam env --shell=fish)"
      ^
from sourcing file ~/.config/fish/config.fish
	called during startup
source: Error while reading file “/home/user/.config/fish/config.fish”

The error from fish suggests "$ ... " is not needed.

fish version is 3.6.0.

https://nix-community.github.io/home-manager/options.html#opt-programs.opam.enableFishIntegration

Maintainer CC

@alois31 @marsam

System information

- system: `"x86_64-linux"`
 - host os: `Linux 5.15.0-58-generic, Ubuntu, 22.04.1 LTS (Jammy Jellyfish), nobuild`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.12.0`
 - channels(root): `"nixpkgs"`
 - channels(bikal): `"home-manager-22.11.tar.gz"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixpkgs`