benefits of extralibs/consequences of exceptions (Re: head aches in parser/Parser.hs)

[Max Bolingbroke]

> Packages that explicitly depend on base-3.x will continue to work.
> Unfortunately these are few and far between, despite our warnings after the
> 6.8 release.

If this was reccomended practice, then I must have missed where it was
documented. In particular, the "Upgrading packages to work with recent
Cabal and GHC versions" link from haskell.org/cabal leads to
http://haskell.org/haskellwiki/Upgrading_packages, which suggests:

"""
library
  if flag(splitBase)
    build-depends: base >= 3, containers
  else
    build-depends: base < 3
"""

Unless my understanding is wrong, this will consume base-4 while
ignoring your new compatibility base-3.

Where should Haskellers be looking to find these reccomendations, if
not on the official Cabal site?

Cheers,
Max