The impossible happened, code commented
initializeWorld = (\w -> do
worldSetGravity w 0 (-1.0) 0
worldSetERP w 0.2
worldSetCFM w 1e-5
worldSetContactMaxCorrectingVel w 0.9
worldSetContactSurfaceLayer w 0.001
worldSetAutoDisableFlag w 1),
these worldSet* functions are unsafe FFI calls. initializeWorld is Ptr Int -> IO ()
commenting this prevents this bug. this code is found in a top level declaration:
initiailLevel = Level {
...
}
of which contains the record for initializeWorld