[Haskell-cafe] ghci: Difference in garbage collection etc. between REPL and function

I have an annoying bug in a C binding that can be triggered like this: handle <- open ... prep <- makePreparedStatement handle "INSERT ..." performGC runStatement prep close handle If I run these steps one by one in ghci, garbage ends up in my handle as expected. However, if I "let main = do ..." this whole block in order to pack it in a test case, it does not happen, neither in ghci nor ghc. What might be the special magic in ghci's REPL that allows me to trigger my bug so easily there? Thanks Niklas