[Haskell] Re: haddock not finding base lib docs -- $topdir ?

[Claus Reinke]

> This is due to the way GHC is installed on Windows, the package database doesn't 
> have hardcoded pathnames, the idea being that you can move your GHC anywhere in 
> the filesystem and it will still work.

this is an essential feature (for instance, running GHC from a USB or network drive, 
or just unpacking snapshots without using installers), please do not start splicing in 
absolute paths!
 
> Unfortunately this means that Haddock can't find the documentation for the packages.

this part I do not understand - if GHC and ghc-pkg can find the packages, why can't 
Haddock? wouldn't it just be a case of making $topdir be in a fixed relationship to the 
output of "ghc --print-libdir"? 

or should there be a way to query ghc-pkg for the list of package location roots? as 
you say, the main docs will be in a known location relative to GHC, but perhaps docs 
in general should be be in a known location relative to their packages, which ghc-pkg 
(or other tools for other implementations) should be able to locate?

> One workaround is to specify the paths by hand, using Haddock's --read-interface 
> flag.  You're using Haddock via Cabal though, so that doesn't work too well. 
> The other workaround is to find GHC's package.conf file and replace the string 
> $topdir with the literal path ("c:/ghc/ghc-6.6" in your case - perhaps you have 
> to append "/doc" for the haddock fields, though).

will all docs be moved into "`ghc --print-libdir`\\doc"? what about local/user
package databases?

Claus