anchor.diff:        haskell-nix.haskellLib.selectProjectPackages staticPackages.hs;
   
       # The top-level set of attributes to build on ci.
  -    finalPackages = dynamicPackages // rec {
  -      # Replace some top-level attributes with their static variant.
  -      inherit (staticPackages) urbit tarball;
  +    finalPackages = rec {
  +      # Expose select packages to increase signal-to-noise of the ci dashboard.
  +      inherit (staticPackages) urbit urbit-tests tarball;
   
  -      # Expose the nix-shell derivation as a sanity check.
  +      # Expose the nix-shell derivation as a sanity check + possible cache hit.
         shell = import ./shell.nix;
   
         # Replace the .hs attribute with the individual collections of components
  
positive.code: 
    # The key with google storage bucket write permission,
    # deployed to ci via nixops `deployment.keys."service-account.json"`.
    serviceAccountKey =
      builtins.readFile ("/var/lib/hercules-ci-agent/secrets/service-account.json");
  
    # Push a split output derivation containing "out" and "hash" outputs.
    pushObject =
  
negative.code:         contentType = "application/x-gtar";
        };
  
        # Top-level pill attributes build and push-to-storage - only on linux.
      } // lib.optionalAttrs (system == "x86_64-linux") {
        ivory = pushPill "ivory" dynamicPackages.ivory;
        brass = pushPill "brass" dynamicPackages.brass;
  