Use spec from hydra-formal-specification (#1548)

.github/workflows/ci-nix.yaml

@@ -276,14 +276,14 @@ jobs:
 
     - name: ❄ Build specification PDF
       run: |
-        nix build .#spec && cp result/*.pdf spec/
+        nix build .#spec && cp result/*.pdf .
 
     - name: 💾 Upload specification
       uses: actions/upload-artifact@v4
       with:
         name: hydra-spec
         path: |
-          ./spec/*.pdf
+          ./*.pdf
 
   documentation:
     name: Documentation

docs/docs/dev/specification.md

@@ -1,6 +1,6 @@
 # Specification
 
-The specification is currently written in LaTeX and can be [edited](https://github.com/cardano-scaling/hydra/tree/master/spec) in the Hydra repository. You can view the rendered version below or download it for fullscreen viewing [here](/hydra-spec.pdf).
+The specification is currently written in LaTeX and can be [edited](https://github.com/cardano-scaling/hydra-formal-specification) in the hydra-formal-specification repository. You can view the rendered version below or download it for fullscreen viewing [here](/hydra-spec.pdf).
 
 import HydraSpecUrl from '@site/static/hydra-spec.pdf';
 

flake.nix

@@ -3,6 +3,7 @@
     nixpkgs.follows = "haskellNix/nixpkgs";
     nixpkgsLatest.url = "github:NixOS/nixpkgs/nixos-24.05";
     haskellNix.url = "github:input-output-hk/haskell.nix";
+    hydra-spec.url = "github:cardano-scaling/hydra-formal-specification";
     iohk-nix.url = "github:input-output-hk/iohk-nix";
     flake-parts.url = "github:hercules-ci/flake-parts";
     process-compose-flake.url = "github:Platonic-Systems/process-compose-flake";
@@ -130,9 +131,7 @@
           packages =
             hydraPackages //
             (if pkgs.stdenv.isLinux then (prefixAttrs "docker-" hydraImages) else { }) // {
-              spec = import ./spec {
-                inherit pkgs;
-              };
+              spec = inputs.hydra-spec.packages.${system}.default;
             };
           process-compose."demo" = import ./nix/hydra/demo.nix {
             inherit system pkgs inputs self;