On Sat, Sep 11, 2010 at 12:17:27PM -0700, Jason Dagit wrote:
From the FAQ linked by Paolo:
http://www.haskell.org/cabal/FAQ.html#dependencies-conflict
"To avoid this problem in the future, avoid upgrading core packages. The latest version of cabal-install has disabled the upgrade command to make it a bit harder for people to break their systems in this way."
It's not always possible. In particular, random-1.0.0.2 (shipped with GHC 6.12.*) depends on the time package, of which more recent versions have been released. That can trigger rebuilding of random-1.0.0.2, and thus haskell98-1.0.1.1. It might help if the release of random with GHC 7.0 had a tight dependency on the version of the time package shipped with it. Maybe all the core packages need tight dependencies.