Smaller required jobs (#990)

We still seem to be getting some OOM errors.  This is likely to be
because some of the required jobs are still very large (with multiple
cross compilation target platforms). Hopefully breaking these out will
help.

Author: hamishmack

release.nix

@@ -26,14 +26,17 @@ let
         let nixpkgsJobs = allJobs.${nixpkgsVer};
         in lib.concatMap (compiler-nix-name:
           let ghcJobs = nixpkgsJobs.${compiler-nix-name};
-          in builtins.map (platform: {
-            name = "required-${nixpkgsVer}-${compiler-nix-name}-${platform}";
-            value = genericPkgs.releaseTools.aggregate {
-              name = "haskell.nix-${nixpkgsVer}-${compiler-nix-name}-${platform}";
-              meta.description = "All ${nixpkgsVer} ${compiler-nix-name} ${platform} jobs";
-              constituents = lib.collect (d: lib.isDerivation d) ghcJobs.${platform};
-            };
-          }) (names ghcJobs)
+          in builtins.concatMap (platform:
+            let platformJobs = ghcJobs.${platform};
+            in builtins.map (crossPlatform: {
+              name = "required-${nixpkgsVer}-${compiler-nix-name}-${platform}-${crossPlatform}";
+              value = genericPkgs.releaseTools.aggregate {
+                name = "haskell.nix-${nixpkgsVer}-${compiler-nix-name}-${platform}-${crossPlatform}";
+                meta.description = "All ${nixpkgsVer} ${compiler-nix-name} ${platform} ${crossPlatform} jobs";
+                constituents = lib.collect (d: lib.isDerivation d) platformJobs.${crossPlatform};
+              };
+           }) (names platformJobs)
+         ) (names ghcJobs)
         ) (names nixpkgsJobs)
       ) (names allJobs));
 in latestJobs // requiredJobs // {