On Wed, Jun 18, 2008 at 4:02 PM, Duncan Coutts <[EMAIL PROTECTED]> wrote: > > > > On Jun 18, 2:24 pm, "Jean-Philippe Bernardy" <[EMAIL PROTECTED]> > wrote: > >> On Wed, Jun 18, 2008 at 2:27 PM, Duncan Coutts <[EMAIL PROTECTED]> wrote: >> > Wed Jun 18 13:22:02 BST 2008 Duncan Coutts <[EMAIL PROTECTED]> >> > * Specifying cabal-version: >=1.5 is not necessary >> > yi.cabal can be processed fine with Cabal-1.2.3.0 >> >> Actually we'd like to build yi with the same version as the one we link >> against, >> so we can open the build-info. >> I comitted an adapted patch. > > Ok, well just make sure you do not distribute it like that. It's far > too fragile to specify one exact version. > > Another thing to note is that cabal-install does not track the cabal- > version as a dependency so it the user does not happen to have 1.4.0.1 > then it will just fail. It will not go and install version 1.4.0.1. > > On a related note, while cabal-install can now install yi-0.3 from > hackage it cannot install 0.4 from darcs because it ends up using two > versions of Cabal. The dependency resolution system is designed to > avoid using multiple versions of dependencies so it cannot find a > solution for yi-0.4. The issue is that cabal-install does not know > that it's ok for yi to depend on one version of Cabal while the ghc > package depends on another. As it happens, it is ok because the ghc > doesn't re-export much stuff from Cabal so you don't tend to bump into > type errors but cabal-install does not have enough information > currently to know that ghc uses Cabal privately. > > So just after making it work for the last set of problem we find > there's no easy solution again. :-( > > The workaround is to do the configure, build and install steps > separately and avoid ever trying to make an install plan (since that > is impossible). > > The longer term solution is for ghc and Cabal to support a notion of a > private build dependency, which is one where things defined in the > dependent package are not re-exported, so it would not matter what > version was used and it would not have to match the version of other > public uses of that package name. >
We'll make sure to depend on the cabal version that comes with ghc 6.10, thereby fixing things for a while. Also, the problem appears only if you specify the flag -shim; I guess that could be false by default. Thanks for the details, and for the effort put into the dependency problem! -- JP --~--~---------~--~----~------------~-------~--~----~ Yi development mailing list [email protected] http://groups.google.com/group/yi-devel -~----------~----~----~----~------~----~------~--~---
