GHC version for next HP

[Duncan Coutts]

Hi all,

So our next release is aimed for May 2012. We obviously want to use a
GHC 7.4.x release. We do not yet know for sure if there will be a
7.4.2 release in time for May. The GHC devs have not decided yet when
to do a 7.4.2 release, but if they know that if they want to target
the HP release that we'd like ~6 weeks lead time.

So we should start testing with 7.4.1 and latest versions of other
libs and see if we have any serious bugs which would force us to wait
for 7.4.2. If there's no serious bugs there's no problem if we use
7.4.1, we can do subsequent minor releases with 7.4.2 or later.

Duncan