From 0e4d9404dde9c56ae346dfc531c8675da107e21c Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Mon, 22 Aug 2022 19:41:08 -0700
Subject: [PATCH] don't create packages for targets that are null

---
 default.nix |  4 +++-
 flake.nix   | 39 ++++++++++++++++++++-------------------
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/default.nix b/default.nix
index a94f16a..9553e45 100644
--- a/default.nix
+++ b/default.nix
@@ -26,7 +26,9 @@ let
   # The packages that are tagged releases
   taggedPackages = lib.attrsets.mapAttrs
     (k: v: mkBinaryInstall { inherit (v.${system}) version url sha256; })
-    (builtins.removeAttrs sources ["master"]);
+    (lib.attrsets.filterAttrs
+      (k: v: (builtins.hasAttr system v) && (v.${system}.url != null))
+      (builtins.removeAttrs sources ["master"]));
 
   # The master packages
   masterPackages = lib.attrsets.mapAttrs'
diff --git a/flake.nix b/flake.nix
index b0e9192..9c7714d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -10,27 +10,28 @@
     # List of systems where binaries are provided.
     let
       systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" ];
-    in flake-utils.lib.eachSystem systems (system:
-      let pkgs = nixpkgs.legacyPackages.${system};
-      in rec {
-        # The packages exported by the Flake:
-        #  - default - latest /released/ version
-        #  - <version> - tagged version
-        #  - master - latest nightly (updated daily)
-        #  - master-<date> - nightly by date
-        packages = import ./default.nix { inherit system pkgs; };
-
-        # "Apps" so that `nix run` works. If you run `nix run .` then
-        # this will use the latest default.
-        apps = rec {
-          default = apps.zig;
-          zig = flake-utils.lib.mkApp { drv = packages.default; };
-        };
+      outputs = flake-utils.lib.eachSystem systems (system:
+        let pkgs = nixpkgs.legacyPackages.${system};
+        in rec {
+          # The packages exported by the Flake:
+          #  - default - latest /released/ version
+          #  - <version> - tagged version
+          #  - master - latest nightly (updated daily)
+          #  - master-<date> - nightly by date
+          packages = import ./default.nix { inherit system pkgs; };
 
+          # "Apps" so that `nix run` works. If you run `nix run .` then
+          # this will use the latest default.
+          apps = rec {
+            default = apps.zig;
+            zig = flake-utils.lib.mkApp { drv = packages.default; };
+          };
+        });
+    in outputs // {
         # Overlay that can be imported so you can access the packages
         # using zigpkgs.master.latest or whatever you'd like.
-        overlay = final: prev: {
-          zigpkgs = packages.${prev.system};
+        overlays.default = final: prev: {
+          zigpkgs = outputs.packages.${prev.system};
         };
-      });
+      };
 }