properly assigns the custom shell

flake.nix

@@ -19,23 +19,34 @@
   outputs = { self, nixpkgs, home-manager, nixvim, nix-gaming, ... }@inputs:
     let
       system = "x86_64-linux";
+      customPkgsOverlay = final: prev: import ./pkgs {
+        pkgs = prev;
+        lib = prev.lib;
+      };
       pkgs = import nixpkgs {
         inherit system;
         config.allowUnfree = true;
+        overlays = [ customPkgsOverlay ];
       };
       lib = nixpkgs.lib;
     in {
       nixosConfigurations = {
         nixos = lib.nixosSystem {
           inherit system;
-          specialArgs = {
-            inherit inputs;
-            inherit system;
-          };
+          specialArgs = { inherit inputs; };
           modules = [
+            { nixpkgs.overlays = [ customPkgsOverlay ]; }
             ./hosts/configuration.nix
           ];
         };
       };
+
+      homeConfigurations = {
+        "cobray" = home-manager.lib.homeManagerConfiguration {
+          inherit pkgs;
+          extraSpecialArgs = { inherit inputs; };
+          modules = [ ./home-manager/cobray.nix ];
+        };
+      };
     };
 }

home-manager/modules/fish.nix

@@ -2,6 +2,7 @@
 
 {
   home.packages = with pkgs; [
+    fish-rust
     starship
     fzf
     bat
@@ -10,7 +11,4 @@
     ripgrep
   ];
 
-  programs.fish = {
-    enable = true;
-  };
 }

modules/default.nix

@@ -7,7 +7,6 @@
     ./boot.nix
     ./docker.nix
     ./env.nix
-    ./fish.nix
     ./fonts.nix
     ./home-manager.nix
     ./i3-xfce.nix

modules/fish.nix

@@ -1,18 +0,0 @@
-{ config, pkgs, lib, ... }:
-let
-  fish-rust = pkgs.callPackage ../pkgs/fish-rust { };
-in
-{
-  programs.fish = {
-    enable = true;
-    package = fish-rust;
-  };
-  environment.systemPackages = with pkgs; [
-    starship
-    fzf
-    bat
-    eza
-    fd
-    ripgrep
-  ];
-}

modules/user.nix

@@ -1,12 +1,16 @@
 { config, pkgs, lib, ... }:
 
+let
+  fish-rust = pkgs.callPackage ../pkgs/fish-rust { };
+in
+
 {
   # Define a user account. Don't forget to set a password with 'passwd'.
   users.users.cobray = {
     isNormalUser = true;
     description = "Mon Aie";
     extraGroups = [ "networkmanager" "wheel" "docker" "video" ];
-    shell = pkgs.fish;
+    shell = fish-rust;
     packages = with pkgs; [
       # User-specific packages can be defined here
       # or through home-manager
@@ -17,4 +21,9 @@
     enable = true;
     wheelNeedsPassword = true;
   };
+
+  programs.fish = {
+    enable = true;
+    package = fish-rust;
+  };
 }

pkgs/fish-rust/default.nix

@@ -1,13 +1,16 @@
-{ lib, rustPlatform, fetchgit, ncurses, sphinx, python3 }:
+{ lib, rustPlatform, fetchgit, ncurses, python3Packages, gettext }:
+
 rustPlatform.buildRustPackage rec {
   pname = "fish";
   version = "4.1-2025-03-14-rust";
+
   src = fetchgit {
     url = "https://github.com/fish-shell/fish-shell.git";
     rev = "refs/heads/master";
     fetchSubmodules = true;
     sha256 = "18zpwa3yddic6wdwj7g51w6n4apwsixfvl179yddk2nwfpxhv4hq";
   };
+
   cargoLock = {
     lockFile = "${src}/Cargo.lock";
     outputHashes = {
@@ -15,26 +18,41 @@ rustPlatform.buildRustPackage rec {
       "pcre2-sys-0.2.9" = "0mhjw7fvrzxb3fd0c534a17qgy6svz0z8269d2fs6q8aw11610mr";
     };
   };
-  buildInputs = [ ncurses ];
-  nativeBuildInputs = [ sphinx python3 ];
+
+  buildInputs = [ ncurses gettext ];
+  nativeBuildInputs = with python3Packages; [
+    sphinx
+    sphinx_rtd_theme
+    gettext
+  ];
+
   preBuild = ''
     export FISH_BUILD_VERSION="${version}"
     export FISH_BUILD_DOCS=1
   '';
+
   postInstall = ''
     export HOME=$(mktemp -d)
     mkdir -p $HOME/.local/share/fish/install
-    $out/bin/fish --install
+
+    if [ ! -f $HOME/.config/fish/config.fish ]; then
+      $out/bin/fish --install
+    fi
+
     mkdir -p $out/share/fish
     cp -r $HOME/.local/share/fish/install/* $out/share/fish/ 2>/dev/null || true
+
     mkdir -p $out/share/fish/tools
     cp $src/share/tools/create_manpage_completions.py $out/share/fish/tools/
     cp $src/share/tools/deroff.py $out/share/fish/tools/
     chmod +x $out/share/fish/tools/create_manpage_completions.py
     chmod +x $out/share/fish/tools/deroff.py
+
     rm -rf $HOME
   '';
+
   doCheck = false;
+
   meta = with lib; {
     description = "The user-friendly command line shell (Rust version)";
     homepage = "https://fishshell.com/";
@@ -42,5 +60,6 @@ rustPlatform.buildRustPackage rec {
     platforms = platforms.unix;
     mainProgram = "fish";
   };
+
   passthru.shellPath = "/bin/fish";
 }