There's currently an issue with Alex happy when they're built with clang cpp rather Than GCC cpp which some folks are trying to hammer out I think.  I think it's a problem in Alex 3.1.2 but not 3.1.0.

Either way: assuming that bug gets sorted out, making sure Haskell platform has a fresher Alex / happy so that Haskell platform can be used to build ghc 7.8 would be a nice thing to have. 

On Sunday, November 17, 2013, Mark Lentczner wrote:

Here is the current status of the 2013.4.0.0 proposal.

Outstanding Issues

We have a few decisions outstanding, and I'd like to have these decided by Nov. 23 (one week).

• fgl - waiting to hear if Ivan will have new version ready in time.
  
• aeson / dlist - there are serveral options -- I'll start a separate thread on this topic.
• alex / happy - I'd like to hear an "okay" from the maintainers on the major version bump

Current Proposed Versions

GHC 7.6.3 -- same as last time (erroneously listed as a version bump last time)

Packages with no changes:

        fgl, haskell-src, html, HUnit,

        mtl, parsec, QuickCheck, random,

        regex-base, regex-compat, regex-posix,

        split, stm, text, transformers,

        xhtml, zlib

Packages held back:

        cgi: 3001.1.7.5 (3001.1.8.4 requires MonadCatchIO-mtl)

Packages with minor version bumps:

        HTTP: 4000.2.8 → 4000.2.9

        network: 2.4.1.2 → 2.4.2.0

        parallel: 3.2.0.3 → 3.2.0.4

        syb: 0.4.0 → 0.4.1

        unordered-containers: 0.2.3.0 → 0.2.3.3

        vector: 0.10.0.1 → 0.10.9.1?

        primitive: 0.5.0.1 → 0.5.1.0?

Packages with major version bumps:

        case-insensitive: 1.0.0.1 → 1.1.0.1

        hashable: 1.1.2.5 → 1.2.1.0

        GLUT: 2.4.0.0 → 2.5.0.1

        GLURaw: 1.3.0.0 → 1.4.0.0

        OpenGL: 2.8.0.0 → 2.9.1.0

        OpenGLRaw: 1.3.0.0 → 1.4.0.0

        alex: 3.0.5 → 3.1.0 pending okay

        happy: 1.18.10 → 1.19.0  pending okay

Cabal:

        Cabal: 1.16.0 → 1.18.1.2 consensus seems to be that this will be okay

        cabal-install: 1.16.0.2 → 1.18.0.2

Platform Packagers:

This is likely to be the last HP source release that contains all the ad hoc scripts for packaging. I canvased the group last time and as I recall, everyone said they just used the .cabal file - and no one used the scripts. I plan to replace them with a new tool built for the needs of the release, and ditch this old set of scripts. If you need 'em, speak now, or forever hold your peace!

— Mark