nix: Add wezterm package override for darwin

Inspired by "Installing WezTerm from Git" on Discourse[1].

[1]: https://discourse.nixos.org/t/installing-wezterm-from-git/35156/12

flake.nix

@@ -72,6 +72,19 @@
 
       formatter = forAllSystems ({ pkgs }: pkgs.nixfmt-rfc-style);
 
+      packages.aarch64-darwin = {
+        wezterm =
+          let
+            pkgs = nixpkgs.legacyPackages.aarch64-darwin;
+          in
+          with pkgs;
+          callPackage ./nix/pkgs/wezterm {
+            # error: package `bitstream-io v2.5.0` cannot be built because it requires
+            # rustc 1.79 or newer, while the currently active rustc version is 1.77.2
+            inherit (nixpkgs-unstable.legacyPackages.${system}) rustPlatform;
+          };
+      };
+
       devShells = forAllSystems (
         { pkgs }:
         {
@@ -131,6 +144,7 @@
         colomar = nix-darwin.lib.darwinSystem {
           specialArgs = {
             inherit determinate neovim-overlay;
+            inherit (self) packages;
           };
           modules = [ ./nix/hosts/colomar ];
         };

nix/hosts/colomar/default.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, packages, ... }:
 {
   imports = [
     ../../modules/profiles/darwin.nix
@@ -23,7 +23,10 @@
     };
   };
 
-  environment.shells = [ pkgs.zsh ];
+  environment = {
+    shells = [ pkgs.zsh ];
+    systemPackages = [ packages.${pkgs.system}.wezterm ];
+  };
 
   # Used for backwards compatibility, similarly to NixOS.
   # Before changing this value read the documentation for this option