per-system derivations for hydra agg job

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

flake.nix

@@ -161,7 +161,7 @@
     rec {
       inherit lib; # for allowing use of custom functions in nix repl
 
-      hydraJobs = import ./hydra/jobs.nix { inherit inputs outputs; };
+      hydraJobs = import ./hydra/jobs.nix { inherit inputs outputs systems; };
       formatter = forEachSystem (system: nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);
 
       nixosConfigurations = genSystems inputs src (src + "/systems");

hydra/jobs.nix

@@ -1,27 +1,45 @@
-{ inputs, outputs }:
+{
+  inputs,
+  outputs,
+  systems,
+}:
 let
-  inherit (inputs.nixpkgs.lib) mapAttrs mapAttrsToList;
+  inherit (inputs.nixpkgs) lib;
   pkgs = inputs.nixpkgs.legacyPackages.x86_64-linux;
 
   getCfg = _: cfg: cfg.config.system.build.toplevel;
   hostToAgg = _: cfg: cfg;
+
+  # get per-system check derivation (with optional postfix)
+  mapSystems =
+    {
+      check,
+      postfix ? "",
+    }:
+    (map (system: if postfix == "" then check.${system} else check.${system}.${postfix}) systems);
 in
 rec {
   inherit (outputs) formatter devShells checks;
 
-  host = mapAttrs getCfg outputs.nixosConfigurations;
+  host = lib.mapAttrs getCfg outputs.nixosConfigurations;
 
   hosts = pkgs.releaseTools.aggregate {
     name = "hosts";
-    constituents = mapAttrsToList hostToAgg host;
+    constituents = lib.mapAttrsToList hostToAgg host;
   };
 
   devChecks = pkgs.releaseTools.aggregate {
     name = "devChecks";
-    constituents = [
-      formatter.x86_64-linux
-      devShells.x86_64-linux
-      checks.x86_64-linux
+    constituents = lib.flatten [
+      (mapSystems { check = formatter; })
+      (mapSystems {
+        check = checks;
+        postfix = "pre-commit-check";
+      })
+      (mapSystems {
+        check = devShells;
+        postfix = "default";
+      })
     ];
   };
 }