Hi all, As discussed before http://www.mail-archive.com/haskell-cafe@haskell.org/msg104498.html, the interface of the MonadCatchIO packages is effectively deprecated by the removal of the 'block' and 'unblock' functions in base-4.7. I would like to deprecate MonadCatchIO-transformers now. As there are quite a few reverse dependencies, and as there is at least one use case that apparently cannot be migrated easily http://www.mail-archive.com/haskell-cafe@haskell.org/msg104501.html, I will try to keep the package functioning, for now. In order to do this, I followed Edward Z. Yang's suggestion, and re- implemented the IO instances of block and unblock, in terms of GHC primitives. The instance now reads

import qualified Control.Exception.Extensible as E import GHC.Base (maskAsyncExceptions#) import GHC.IO (unsafeUnmask,IO(IO))

instance MonadCatchIO IO where catch = E.catch block = \ (IO io) -> IO $ maskAsyncExceptions# io unblock = unsafeUnmask

You can get a release candidate for a new version 0.3.1.0, by darcs get http://patch-tag.com/r/AriePeterson/MonadCatchIO-transformers I would be most grateful if someone could review and/or test this under GHC 7.8! Regards, Arie