Fix buildkite

Author: hamishmack

build.nix

@@ -10,9 +10,7 @@
 , pkgsForHydra ? import nixpkgsForHydra (nixpkgsArgs // { inherit (pkgs) system; })
 , ifdLevel ? 1000
 , compiler-nix-name ? throw "No `compiler-nix-name` passed to build.nix"
-, compat
-, system
-, haskellNix ? compat { inherit system; }
+, haskellNix ? (import ./default.nix {})
 }:
 
 let

ci.nix

@@ -78,7 +78,7 @@ dimension "Nixpkgs version" nixpkgsVersions (nixpkgsName: nixpkgs-pin:
       evalPackages = import pinnedNixpkgsSrc nixpkgsArgs;
   in dimension "GHC version" (compilerNixNames nixpkgsName evalPackages) (compiler-nix-name: {runTests}:
       let pkgs = import pinnedNixpkgsSrc (nixpkgsArgs // { inherit system; });
-          build = import ./build.nix { inherit pkgs evalPackages ifdLevel compiler-nix-name compat system; };
+          build = import ./build.nix { inherit pkgs evalPackages ifdLevel compiler-nix-name haskellNix; };
           platformFilter = platformFilterGeneric pkgs system;
       in filterAttrsOnlyRecursive (_: v: platformFilter v && !(isDisabled v)) ({
         # Native builds
@@ -98,7 +98,7 @@ dimension "Nixpkgs version" nixpkgsVersions (nixpkgsName: nixpkgs-pin:
       dimension "Cross system" (crossSystems nixpkgsName evalPackages compiler-nix-name) (crossSystemName: crossSystem:
         # Cross builds
         let pkgs = import pinnedNixpkgsSrc (nixpkgsArgs // { inherit system crossSystem; });
-            build = import ./build.nix { inherit pkgs evalPackages ifdLevel compiler-nix-name compat system; };
+            build = import ./build.nix { inherit pkgs evalPackages ifdLevel compiler-nix-name haskellNix; };
         in pkgs.recurseIntoAttrs (pkgs.lib.optionalAttrs (ifdLevel >= 1) ({
             roots = pkgs.haskell-nix.roots' compiler-nix-name ifdLevel;
             ghc = pkgs.buildPackages.haskell-nix.compiler."${compiler-nix-name}";