:: IO_a_ -> _ IO_ThreadId package:envelope

throwEnvelopeErr' :: (MonadError (Err e) m) => e -> m a
envelope Web.Envelope
Like throwEnvelopeErr but without providing a message. 
>>> import Control.Monad.Except (runExcept)

>>> throwEnvelopeErr "BAD_ERROR" "a very bad error occurred!" :: Either (Err String) Int
Left (Err {errErr = "BAD_ERROR", errExtra = Just "a very bad error occurred!"})