diff --git a/flake.nix b/flake.nix
index cdb65042..ecfc7e04 100644
--- a/flake.nix
+++ b/flake.nix
@@ -163,8 +163,13 @@
         devShellsWithEvalOnLinux = devShellsWithToolsModule { evalSystem = "x86_64-linux"; };
       in {
         inherit devShells;
-        hydraJobs = devShells //
-          (pkgs.lib.mapAttrs' (name: drv:
+        hydraJobs = devShells // {
+          # *-dev sentinel job. Singals all -env have been built.
+          required = pkgs.runCommand "test-dependencies" {
+              _hydraAggregate = true;
+              constituents = map (name: "${system}.${name}-env") (builtins.attrNames devShellsWithEvalOnLinux);
+            } "touch  $out";
+          } // (pkgs.lib.mapAttrs' (name: drv:
             pkgs.lib.nameValuePair "${name}-env" (
             let env = pkgs.runCommand "${name}-env.sh" {
                 requiredSystemFeatures = [ "recursive-nix" ];