lib/filterPackages: filter by flake requirements

returns only non-broken derivations that support the system.

lib/attrs.nix

@@ -26,4 +26,13 @@ rec {
     });
 
   concatAttrs = lib.fold (attr: sum: lib.recursiveUpdate sum attr) { };
+
+  # Filter out packages that support given system and follow flake check requirements
+  filterPackages = system: packages:
+    let
+      # Everything that nix flake check requires for the packages output
+      filter = (n: v: with v; let platforms = meta.hydraPlatforms or meta.platforms or [ ]; in
+        lib.isDerivation v && !meta.broken && builtins.elem system platforms);
+    in
+      lib.filterAttrs filter packages;
 }

lib/default.nix

@@ -17,7 +17,8 @@ lib.makeExtensible (final:
     lists = callLibs ./lists.nix;
     strings = callLibs ./strings.nix;
 
-    inherit (attrs) mapFilterAttrs genAttrs' pathsToImportedAttrs concatAttrs;
+    inherit (attrs) mapFilterAttrs genAttrs'
+      pathsToImportedAttrs concatAttrs filterPackages;
     inherit (lists) pathsIn;
     inherit (strings) rgxToString;
   })