[World__ may only be created with a 'case' statement, it may not be let-bound
John Meacham <john@repetae.net>**20060313123613] hunk ./lib/base/Jhc/IO.hs 44
-unsafePerformIO x = case errorContinuation x of
-    IO y -> case y undefinedIOErrorCont (newWorld__ x) of
-        JustIO _ a -> a
+unsafePerformIO x = case newWorld__ x of
+    world -> case errorContinuation x of
+        IO y -> case y undefinedIOErrorCont world of
+            JustIO _ a -> a