Try NixOS/hydra#715

bors.toml

@@ -1,22 +1,6 @@
 status = [
   "buildkite/haskell-dot-nix",
-  # Generasted in `nix repl` with
-  # __trace (builtins.concatStringsSep "\n" (builtins.map (n: "  \"ci/hydra:Cardano:haskell-nix:${n}\",") (builtins.attrNames (import ./release.nix {})))) {}
-  # TODO automate updating
-  "ci/hydra:Cardano:haskell-nix:required-R2003-ghc865-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2003-ghc865-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc8101-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc8101-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc8102-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc8102-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc810220201118-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc810220201118-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc865-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc865-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc883-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc883-linux",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc884-darwin",
-  "ci/hydra:Cardano:haskell-nix:required-R2009-ghc884-linux",
+  "ci/hydra:Cardano:haskell-nix:required",
 ]
 timeout_sec = 7200
 required_approvals = 1

release.nix

@@ -36,6 +36,13 @@ let
           }) (names ghcJobs)
         ) (names nixpkgsJobs)
       ) (names allJobs));
-in latestJobs // requiredJobs
+in latestJobs // requiredJobs // {
+    required = genericPkgs.releaseTools.aggregate {
+      name = "haskell.nix-required";
+      meta.description = "All jobs required to pass CI";
+      # Using the names here requires https://github.com/NixOS/hydra/issues/715
+      constituents = builtins.attrNames requiredJobs;
+    };
+ }