Homebrew/homebrew — pull request #25451 by Jonplussed (2013-12-25 06:01:00+00:00)
Title: haskell-platform 2013.2.0.0 - additional caveats

Executables installed via Cabal, including updated versions of
cabal-install, reside by default in ~/.cabal/bin, which can cause
confusion for newer users when repeated attempts to update Cabal appear
to silently fail. Remedy this confusion by instructing users to prepend
~/.cabal/bin to their $PATH.