GHC HEAD vs Hackage, panic-free edition

[Sven Panne]

2013/10/15 Bryan O'Sullivan <bos at serpentine.com>:
> It's always good to fix this kind of thing early, as doing so makes it
> possible to find even sooner the real problems that will otherwise remain
> hidden by mickey mouse stuff like bad package dependencies. Finding problems
> before a release is cut is way cheaper (even for open source volunteers)
> than discovering them once the code is in the wild.

Agreed, but how are package maintainers supposed to find out problems
early without much hassle? For my part, I am using Travis CI, but
AFAICT it supports only GHC 7.4.1
(https://github.com/travis-ci/travis-ci/issues/882). There might be
some cruel hacks like downloading some binary builds from somewhere
etc., but this is not a real solution and takes ages.

It would be very cool if Travis CI supported multiple GHC versions,
including a version close to HEAD.