Cyclical dependencies aren't reported in pure functions

No compile error. found in 7.10.2

main :: IO ()
main = do
  putStrLn $ "Hello " ++ (show x)
  where
    x = y + 1
    y = x + 1

Trac metadata

Trac field	Value
Version	7.10.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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