Include pre-existing, libs, pkgconfig and frameworks for shell

Author: hamishmack

builder/shell-for.nix

@@ -114,9 +114,10 @@ let
   # Set up a "dummy" component to use with ghcForComponent.
   component = {
     depends = packageInputs;
-    libs = [];
-    pkgconfig = [];
-    frameworks = [];
+    pre-existing = lib.concatMap (x: (haskellLib.dependToLib x).config.pre-existing or []) packageInputs;
+    libs         = lib.concatMap (x: (haskellLib.dependToLib x).config.libs or []) packageInputs;
+    pkgconfig    = lib.concatMap (x: (haskellLib.dependToLib x).config.pkgconfig or []) packageInputs;
+    frameworks   = lib.concatMap (x: (haskellLib.dependToLib x).config.frameworks or []) packageInputs;
     doExactConfig = false;
   };
   configFiles = makeConfigFiles {