Use nix-locate for command-not-found

common/default.nix

@@ -1,6 +1,8 @@
 { config, pkgs, ... }:
 
-{
+let
+  nix-locate = config.inputs.nix-locate.defaultPackage.${config.currentSystem};
+in {
   imports = [
     ./flakes.nix
     ./pia.nix
@@ -43,6 +45,7 @@
     micro
     helix
     lm_sensors
+    nix-locate
   ];
 
   nixpkgs.config.allowUnfree = true;
@@ -63,8 +66,25 @@
 
   nix.gc.automatic = true;
 
-  programs.fish.enable = true;
-  programs.fish.shellInit = ''
-    set fish_greeting
-  '';
+  programs.command-not-found.enable = false;
+
+  programs.fish = {
+    enable = true;
+
+    shellInit = let
+      wrapper = pkgs.writeScript "command-not-found" ''
+        #!${pkgs.bash}/bin/bash
+        source ${nix-locate}/etc/profile.d/command-not-found.sh
+        command_not_found_handle "$@"
+      '';
+    in ''
+      # use nix-locate for command-not-found functionality
+      function __fish_command_not_found_handler --on-event fish_command_not_found
+          ${wrapper} $argv
+      end
+
+      # disable annoying fish shell greeting
+      set fish_greeting
+    '';
+  };
 }

common/flakes.nix

@@ -16,6 +16,9 @@ in {
 
       # pin nixpkgs for system commands such as "nix shell"
       registry.nixpkgs.flake = config.inputs.nixpkgs;
+
+      # pin system nixpkgs to the same version as the flake input
+      nixPath = [ "nixpkgs=${config.inputs.nixpkgs}" ];
     };
   };
 }

flake.lock

@@ -82,6 +82,22 @@
         "url": "https://git.neet.dev/zuckerberg/dailybuild_modules.git"
       }
     },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1641205782,
+        "narHash": "sha256-4jY7RCWUoZ9cKD8co0/4tFARpWB+57+r1bLLvXNJliY=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "b7547d3eed6f32d06102ead8991ec52ab0a4f1a7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "locked": {
         "lastModified": 1648297722,
@@ -97,6 +113,27 @@
         "type": "github"
       }
     },
+    "nix-locate": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1647808006,
+        "narHash": "sha256-aBlJcylH7/MDiu0RVEiUwV1XufGfVk4OvsFutImCszY=",
+        "owner": "bennofs",
+        "repo": "nix-index",
+        "rev": "e7c66ba52fcfba6bfe51adb5400c29a9622664a2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "bennofs",
+        "repo": "nix-index",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1649117019,
@@ -191,6 +228,7 @@
         "archivebox": "archivebox",
         "dailybuild_modules": "dailybuild_modules",
         "flake-utils": "flake-utils",
+        "nix-locate": "nix-locate",
         "nixpkgs": "nixpkgs",
         "nixpkgs-unstable": "nixpkgs-unstable",
         "radio": "radio",

flake.nix

@@ -5,6 +5,9 @@
 
     flake-utils.url = "github:numtide/flake-utils";
 
+    nix-locate.url = "github:bennofs/nix-index";
+    nix-locate.inputs.nixpkgs.follows = "nixpkgs";
+
     # mail server
     simple-nixos-mailserver.url = "gitlab:simple-nixos-mailserver/nixos-mailserver/nixos-21.11";
     simple-nixos-mailserver.inputs.nixpkgs.follows = "nixpkgs";
@@ -43,7 +46,9 @@
         inputs.dailybuild_modules.nixosModule
         inputs.archivebox.nixosModule
         ({ lib, ... }: {
-          config.environment.systemPackages = [ inputs.agenix.defaultPackage.${system} ];
+          config.environment.systemPackages = [
+            inputs.agenix.defaultPackage.${system}
+          ];
 
           # because nixos specialArgs doesn't work for containers... need to pass in inputs a different way
           options.inputs = lib.mkOption { default = inputs; };