Failure compiling ghc-mtl with ghc-7.8.{2,3}

2014-07-20 Thread i hamsa
I was trying to upgrade to ghc-7.8 the other day, and got this compilation failure when building ghc-mtl-1.2.1.0 (see the end of the message). I'm using the haskell overlay on Gentoo Linux straight out of the box, no local cabal installations of anything. Now I was told that other people can

Re: Avoiding BlockedIndefinitelyOnSTM exceptions

2014-07-20 Thread Neil Davies
Wren That is sort of idea I was alluding to - there is a communication scope, the set of things that now need be cleaned up. In designing systems I'm always aggregating scope of failures to create “units of redundancy” and handling / recovering (and making sure failure within that scope

Re: Failure compiling ghc-mtl with ghc-7.8.{2,3}

2014-07-20 Thread Edward Z . Yang
The last time I saw this error, it was because the package database was messed up (there was an instance of MonadIO in scope, but it was for the wrong package.) However, I don't know what the source of the problem is here. Edward Excerpts from i hamsa's message of 2014-07-20 08:26:52 +0100: I

Re: Failure compiling ghc-mtl with ghc-7.8.{2,3}

2014-07-20 Thread i hamsa
I think I found the problem. package ghc-7.8.3 requires transformers-0.3.0.0 package mtl-2.2.1 requires transformers-0.4.1.0 package exceptions-0.6.1 requires transformers-0.4.1.0 I wonder how is this ever supposed to work :( On Sun, Jul 20, 2014 at 9:01 PM, Edward Z. Yang ezy...@mit.edu wrote:

Re: Failure compiling ghc-mtl with ghc-7.8.{2,3}

2014-07-20 Thread Edward Z . Yang
It looks like you will have to install old versions of mtl/exceptions which work on transformers-0.3.0.0, although undoubtedly the real problem is that GHC should update what version of transformers it is distributing. Edawrd Excerpts from i hamsa's message of 2014-07-20 19:25:36 +0100: I think

Re: Avoiding BlockedIndefinitelyOnSTM exceptions

2014-07-20 Thread Gábor Lehel
On Sun, Jul 20, 2014 at 5:48 AM, wren romano winterkonin...@gmail.com wrote: On Sat, Jul 19, 2014 at 11:24 PM, wren romano winterkonin...@gmail.com wrote: -- | The second argument allows handling 'BlockedIndefinitelyOnSTM' etc. runSTSTM :: (forall s. STSTM s a) - (STMError - b) - b

Re: Avoiding BlockedIndefinitelyOnSTM exceptions

2014-07-20 Thread wren romano
On Sun, Jul 20, 2014 at 5:22 PM, Gábor Lehel glaebho...@gmail.com wrote: On Sun, Jul 20, 2014 at 5:48 AM, wren romano winterkonin...@gmail.com wrote: On Sat, Jul 19, 2014 at 11:24 PM, wren romano winterkonin...@gmail.com wrote: -- | The second argument allows handling