error with package ghc-6.10.1 and its dependency on process-1.0.1.[01]

allan a.d.clark at
Tue Nov 25 05:20:49 EST 2008

Hi Duncan and Thomas

Thanks for the help, unfortunately:
allan at delgado:~$ ghc-pkg unregister --user Cabal-
Writing new package config file... done.

allan at delgado:~$ cabal install haddock
Resolving dependencies...
cabal: dependencies conflict: ghc-6.10.1 requires process == however
process- was excluded because ghc-6.10.1 requires process ==

allan at delgado:~$ ghc-pkg unregister Cabal-
ghc-pkg: unregistering Cabal- would break the following packages: haddock-2.3.0 ghc-6.10.1 (use --

I tried to unregister haddock and then ghc and tried to re-register ghc (by doing 'make install' in the ghc source directory).
Unfortunately this put me back in the same place again.

To provide a bit more information this all comes from a recent upgrade to ghc-6.10.1.
As you can see from the package listing in the previous mail, there aren't that many installed packages (over those installed by ghc).
It seems a little strange that this is not a problem for everyone else. It looks to me (albeit inexperienced) that the error occurs during the ghc "make install" target, but then if that were the case I can't see why the same thing wouldn't happen to everyone.


Duncan Coutts wrote:
> On Mon, 2008-11-24 at 20:05 +0000, Thomas Schilling wrote:
>> Could it be that the cabal gets confused because there are two
>> versions of Cabal- but which probably depend on two different
>> versions of process?
> That could well be it. The user and global package dbs simply get
> overlayed so identical package versions in the user-db mask ones in the
> global db. So that would indeed mean that cabal would think that the ghc
> global package depended on the Cabal package from the user db, which is
> built against the different version of the process lib.
> So the workaround for Allan would be to unregister the Cabal-
> from the user db: ghc-pkg unregister --user Cabal-
> and probably to rebuild anything that depends on it.
> We'll have to think about if there's a better way to manage this. In the
> longer term I'd like to use hashes to identify installed packages but
> for now...
> Duncan

The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.

More information about the cabal-devel mailing list