More fixes for shellFor

Author: hamishmack

builder/ghc-for-component-wrapper.nix

@@ -147,7 +147,7 @@ let
   drv = runCommand "${componentName}-${ghc.name}-env" {
   preferLocalBuild = true;
   passthru = {
-    inherit targetPrefix;
+    inherit script targetPrefix;
     inherit (ghc) version meta;
   };
   propagatedBuildInputs = configFiles.libDeps;

builder/make-config-files.nix

@@ -204,6 +204,10 @@ let
   drv = runCommand "${ghc.targetPrefix}${fullName}-config" {
       nativeBuildInputs = [ghc];
       propagatedBuildInputs = libDeps;
+      passthru = {
+        inherit (ghc) targetPrefix;
+        inherit script libDeps ghcCommand ghcCommandCaps libDir packageCfgDir component;
+      };
     } (''
     mkdir -p $out
     configFiles=$out

builder/shell-for.nix

@@ -182,8 +182,8 @@ in
 
     passthru = (mkDrvArgs.passthru or {}) // {
       ghc = ghcEnv.drv;
-      inherit configFiles;
+      configFiles.drv;
     };
   } // lib.optionalAttrs exactDeps {
-    CABAL_CONFIG = "${configFiles}/cabal.config";
+    CABAL_CONFIG = "${configFiles.drv}/cabal.config";
   })