Add flake.nix

flake.lock

@@ -0,0 +1,9 @@
+{
+    "nonFlakeRequires": {},
+    "requires": {
+        "nixpkgs": {
+            "uri": "github:edolstra/nixpkgs/a4d896e89932e873c4117908d558db6210fa3b56"
+        }
+    },
+    "version": 1
+}

flake.nix

@@ -0,0 +1,21 @@
+{
+  name = "hydra";
+
+  description = "A Nix-based continuous build system";
+
+  epoch = 2019;
+
+  requires = [ "nixpkgs" ];
+
+  provides = deps: rec {
+
+    hydraJobs = import ./release.nix {
+      hydraSrc = deps.self;
+      nixpkgs = deps.nixpkgs;
+    };
+
+    packages.hydra = hydraJobs.build.x86_64-linux;
+
+    defaultPackage = packages.hydra;
+  };
+}

release.nix

@@ -30,7 +30,8 @@ let
       environment.systemPackages = [ pkgs.perlPackages.LWP pkgs.perlPackages.JSON ];
     };
 
-  version = builtins.readFile ./version + "." + toString hydraSrc.revCount + "." + hydraSrc.rev;
+  # FIXME: use commit date.
+  version = builtins.readFile ./version + "." + toString hydraSrc.revCount or 0 + "." + hydraSrc.shortRev or "0000000";
 
 in