[Haskell] Haddock not being able to read interface file

[Wolfgang Jeltsch]

Hello,

I want to generate Haddock documentation for some Haskell files and want to 
create hyperlinks to the base package’s documentation.  I’ve downloaded 
<http://www.haskell.org/ghc/docs/latest/html/libraries/base/base.haddock> and 
use the option

    --read-interface=http://www.haskell.org/ghc/docs/latest/html/libraries/base,base.haddock

in my Haddock command line.  However, Haddock outputs the following:

    haddock: Warning: The interface file "base.haddock" could not be read.
    Maybe it's from a later version of Haddock?

This happens with Haddock 0.8 as well as the current development version of 
Haddock.

What’s wrong here?

Best wishes,
Wolfgang