StateT space leak

[Wojtek Moczydlowski]

Consider the following program:

module A where

import Control.Monad.State

f :: StateT Int IO ()
f = (sequence_ $ repeat $ return ())

t = runStateT f 0


When t is evaluated under ghci or hugs, the program quickly runs out of heap
memory. What's going on here? Is this inherent in StateT monad? If so, then
this is very surprising, I would expect f to run in constant space for any
sensible monad.

Wojtek