[Haskell-cafe] cabal install pandoc

[Albert Y. C. Lai]

On 13-04-01 06:26 AM, Roger Mason wrote:
> It turned out that there was a stale version of 'array' lurking in the
> ghc package db.  In spite of reinstalling ghc it did not go away until I
> unregistered it.  I think it was persisting because re-installing ghc
> simply unpacked over the old directory leaving that pre-existing file
> intact.

See my http://www.vex.net/~trebla/haskell/sicp.xhtml for how does GHC 
know or not know what libs you have. In particular, it has very little 
to do with files, and clearing GHC is only half the story.

And how to have the same kind of problems recur in the future.