Fix hadrianEvalPackages

Author: hamishmack

build.nix

@@ -28,11 +28,9 @@ in rec {
       });
     } // pkgs.lib.optionalAttrs (__compareVersions haskell.compiler.${compiler-nix-name}.version "9.4" >= 0) {
       # Make sure the plan for hadrian is cached (we need it to instanciate ghc).
-      hadrian-plan = (pkgs.haskell-nix.compiler.${compiler-nix-name}.hadrian.project.appendModule [{
-        compilerSelection = p: builtins.mapAttrs.override { hadiranEvalPackages = evalPackages; } p.haskell-nix.compiler;
-      }]).plan-nix;
+      hadrian-plan = pkgs.haskell-nix.compiler.${compiler-nix-name}.hadrianProject.plan-nix;
       # Also include the same plan evaluated on the eval system (probably x86_64-linux).
-      hadrian-plan-eval = (pkgs.haskell-nix.compiler.${compiler-nix-name}.override { hadrianEvalPackages = evalPackages; }).hadrian.project.plan-nix;
+      hadrian-plan-eval = (pkgs.haskell-nix.compiler.${compiler-nix-name}.override { hadrianEvalPackages = evalPackages; }).hadrianProject.plan-nix;
     } // pkgs.lib.optionalAttrs (__compareVersions haskell.compiler.${compiler-nix-name}.version "9.8" < 0) {
       hlint-latest = tool compiler-nix-name "hlint" {
         inherit evalPackages;

compiler/ghc/default.nix

@@ -254,7 +254,8 @@ let
   # value for us.
   installStage1 = useHadrian && (with haskell-nix.haskellLib; isCrossTarget || isNativeMusl);
 
-  hadrian =
+  hadrianProject =
+    assert (hadrianEvalPackages.system == "x86_64-linux");
     let
       compiler-nix-name =
         if builtins.compareVersions ghc-version "9.4.7" < 0
@@ -263,7 +264,9 @@ let
           then "ghc964"
         else "ghc962";
     in
-    buildPackages.haskell-nix.tool compiler-nix-name "hadrian" {
+    buildPackages.haskell-nix.cabalProject' {
+      inherit compiler-nix-name;
+      name = "hadrian";
       compilerSelection = p: p.haskell.compiler;
       index-state = buildPackages.haskell-nix.internalHackageIndexState;
       evalPackages = hadrianEvalPackages;
@@ -296,6 +299,8 @@ let
       };
     };
 
+  hadrian = hadrianProject.hsPkgs.hadrian.components.exes.hadrian;
+
   # For a discription of hadrian command line args
   # see https://gitlab.haskell.org/ghc/ghc/blob/master/hadrian/README.md
   # For build flavours and flavour transformers
@@ -663,7 +668,7 @@ haskell-nix.haskellLib.makeCompilerDeps (stdenv.mkDerivation (rec {
     '';
 
   passthru = {
-    inherit bootPkgs targetPrefix libDir llvmPackages enableShared useLLVM hadrian;
+    inherit bootPkgs targetPrefix libDir llvmPackages enableShared useLLVM hadrian hadrianProject;
 
     # Our Cabal compiler name
     haskellCompilerName = "ghc-${version}";