Hi folks, Over the weekend Lennart Kolmodin tested all of Gentoo's Haskell packages with the latest GHC 6.6 RC snapshot. Here is his report of what failed, and how: http://www.haskell.org/~gentoo/gentoo-haskell/projects/GHC-6.5-failures.html You'll note that there are some common ones, like Data.FiniteMap going away and the old API in Data.Set disappearing. There seemed to be several programs which used the old lang or text packages. The change in the array bounds api broke some things. Text.Regex moved into a different package. Most of these look fairly trivial. Class instance changes broke a couple packages, which might be a bit more tricky to fix. One Cabal api change broke one package, again easily fixable. We made some Cabal modules that had been private by convention properly private (ei Distribution.Compat.*). This broke lhs2tex. I'm not sure exactly what Cabal scripts should be using for portable file path handling since Setup.hs modules are not supposed to have external dependencies on other packages (otherwise there's a chicken and egg problem with compiling Setup.hs). Advice here would be apreciated, I could let Distribution.Compat.FilePath remain public in this release and seek a better solution for the next release. BTW, you can see the complete set of Gentoo's Haskell packages here: http://www.haskell.org/~gentoo/gentoo-haskell/ (mostly under dev-haskell/) Gentoo users & developers can use this package collection as a portage overlay. Duncan (wearing his Cabal release manager hat and his Gentoo hat)