First: Yes, I really do mean to install install just GHC, and not the Haskell Platform. I am installing in a VM made just for this purpose, I have the platform installed elsewhere.
So the standard instructions for installing from a distro mentions ghc6 which is not recognized as a valid target (anymore?). So if I install the ghc package instead, I (successfully) get 7.6.3.
I did make sure that I have universe enabled, and have the latest package list. Is it that 7.8.2 is not packaged yet?