This is perhaps a minor nuisance but I had to spendquite some time to track down my bug. When ghc is givena preprocessor which for some reason cannot executethen ghc just dies silently without giving anyindication as to what the problem was. It would be nicewith a little message hinting at the problem on stderr.Oh, and by the way, the -F flag doesn't have anydocumentation. It is only mentioned together with -optF.