úάp%Generating stack traces for failures 8 records the given source location in the failure trace > if the underlying monad supports recording location traces + is a convenient TH macro which expands to  <source location> L It should only be used when the MonadLoc preprocessor is not available.  Usage:   f x = $withLocTH $ do ! $withLocTH $ something + x < -$withLocTH $ something-else  ... GNOTE: unfortunately type signatures are necessary when using withLocTH  monadloc-0.3Control.Monad.LocMonadLocwithLoc withLocTHshowLoc