Update cross-windows to use nixpkgs-mozilla.

.gitignore

@@ -1,2 +1,3 @@
 docparse/target
 /flake.lock
+result

examples/cross-windows/flake.nix

@@ -1,28 +1,33 @@
 {
   inputs = {
-    fenix = {
-      url = "github:nix-community/fenix";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
-    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = github:NixOS/nixpkgs/nixpkgs-unstable;
     naersk = {
-      url = "github:nmattia/naersk";
+      url = github:nmattia/naersk;
       inputs.nixpkgs.follows = "nixpkgs";
     };
-    nixpkgs.url = "nixpkgs/nixpkgs-unstable";
+    nixpkgs-mozilla = {
+      url = github:mozilla/nixpkgs-mozilla;
+      flake = false;
+    };
+    flake-utils.url = github:numtide/flake-utils;
   };
 
-  outputs = { self, fenix, flake-utils, naersk, nixpkgs }:
+  outputs = { self, nixpkgs, naersk, nixpkgs-mozilla, flake-utils }:
     flake-utils.lib.eachDefaultSystem (
       system: {
         defaultPackage = let
-          pkgs = nixpkgs.legacyPackages.${system};
-          toolchain = with fenix.packages.${system};
-            combine [
-              minimal.rustc
-              minimal.cargo
-              targets.x86_64-pc-windows-gnu.latest.rust-std
-            ];
+          pkgs = import nixpkgs {
+            inherit system;
+            overlays = [ (import nixpkgs-mozilla) ];
+          };
+          rustChannel = pkgs.rustChannelOf {
+            channel = "nightly";
+            date = "2021-03-24";
+            sha256 = "0y7ijxqbjac9gn038lihlcq7ynsvgi3f8fzn06bhmqhvww5dbwzn";
+          };
+          toolchain = rustChannel.rust.override {
+            targets = [ "x86_64-pc-windows-gnu" "x86_64-unknown-linux-musl" ];
+          };
           naersk-lib = naersk.lib.${system}.override {
             cargo = toolchain;
             rustc = toolchain;