> It doesn't appear to be either of these.  My own projects use no form of
> pre-processing and exhibit exactly the same problem: a parse error on
> first character of the line after the first Haddock comment.  I don't
> know if the Haddock project itself (whose output I put up here) uses
> pre-processing, but I know for a fact my code does not.

The haddock project does.

Parse error on the first line after a Haddock comment is a givaway that
you have bad haddock syntax, either in the comment itself or possibly
the .cabal file (you need to escape slashes in the package description -
that was a big pain to figure out for me).