Hi all, I couldn't see a way to write any of these functions without using GHC.IOBase. Did I miss one? If not, can they (or something that would allow them to be written) please be added to System.IO.Error? import GHC.IOBase ( IOException(ioe_location), IOErrorType(UnsupportedOperation, HardwareFault) ) add_to_error_loc :: Exception -> String -> Exception add_to_error_loc (IOException ioe) s = IOException $ ioe { ioe_location = s ++ ": " ++ ioe_location ioe } add_to_error_loc e _ = e isUnsupportedOperationError :: IOError -> Bool isUnsupportedOperationError = isUnsupportedOperationErrorType . ioeGetErrorType isUnsupportedOperationErrorType :: IOErrorType -> Bool isUnsupportedOperationErrorType UnsupportedOperation = True isUnsupportedOperationErrorType _ = False Thanks Ian