[Haskell-cafe] Space leak with unsafePerformIO

Attached is a program with a space leak that I do not understand. I have coded a simple 'map' function, once using unsafePerformIO and once without. UnsafePerformIO has a space leak in some circumstances. In the main program I demonstrate cases with and without space leak. Without space leak the program writes a file to the disk until it is full. Any idea? The original problem is a function that is compiled by LLVM and shall be applied to a list in a mapAccumL manner.