Use mkOverride 900 for project flags.

See input-output-hk/haskell.nix#254

Author: hamishmack

plan2nix/Plan2Nix.hs

@@ -106,7 +106,8 @@ plan2nix args (Plan { packages, extras, compilerVersion, compilerPackages }) = d
                return $ fromString pkg $= mkPath False nix
     _ -> return []
   let flags = concatMap (\case
-          (name, Just (Package v r flags _)) -> flags2nix name flags) $ Map.toList extras
+          (name, Just (Package _v _r f _)) -> flags2nix name f
+          _ -> []) $ Map.toList extras
 
   return $ mkNonRecSet [
     "pkgs" $= ("hackage" ==> mkNonRecSet (
@@ -119,7 +120,7 @@ plan2nix args (Plan { packages, extras, compilerVersion, compilerPackages }) = d
       ]))
     , "extras" $= ("hackage" ==> mkNonRecSet [ "packages" $= extrasNix ])
     , "modules" $= mkList [
-        mkNonRecSet [ "packages" $= mkNonRecSet flags ]
+        mkParamset [("lib", Nothing)] True ==> mkNonRecSet [ "packages" $= mkNonRecSet flags ]
       ]
     ]
  where
@@ -166,7 +167,7 @@ plan2nix args (Plan { packages, extras, compilerVersion, compilerPackages }) = d
 flags2nix :: Text -> HashMap Text Bool -> [Binding NExpr]
 flags2nix pkgName pkgFlags =
   [ quoted pkgName $= mkNonRecSet
-    [ "flags" $= mkNonRecSet [ quoted flag $= mkBool val
+    [ "flags" $= mkNonRecSet [ quoted flag $= ("lib" @. "mkOverride" @@ mkInt 900 @@ mkBool val)
                              | (flag, val) <- Map.toList pkgFlags
                              ]
     ]

stack2nix/Stack2nix.hs

@@ -78,7 +78,7 @@ stack2nix args stack@(Stack resolver compiler _ _) =
                    ++ [ "compiler.nix-name" $= fromString (quoted name)
                       | (Just c) <- [compiler], let name = filter (`elem` ((['a'..'z']++['0'..'9']) :: [Char])) c]))
        , "resolver"  $= fromString (quoted resolver)
-       , "modules" $= mkList [ mkNonRecSet [ "packages" $= mkNonRecSet flags ] ]
+       , "modules" $= mkList [ mkParamset [("lib", Nothing)] True ==> mkNonRecSet [ "packages" $= mkNonRecSet flags ] ]
        ] ++ [
          "compiler" $= fromString (quoted c) | (Just c) <- [compiler]
        ]
@@ -109,7 +109,7 @@ extraDeps2nix (Stack _ _ pkgs _) =
 flags2nix :: Stack -> [Binding NExpr]
 flags2nix (Stack _ _ _ pkgFlags) =
   [ quoted pkgName $= mkNonRecSet
-    [ "flags" $= mkNonRecSet [ quoted flag $= mkBool val
+    [ "flags" $= mkNonRecSet [ quoted flag $= ("lib" @. "mkOverride" @@ mkInt 900 @@ mkBool val)
                              | (flag, val) <- HM.toList flags
                              ]
     ]