Yesod GHC version

I have an emp开发者_开发技巧ty dir that I initialized a Yesod 0.9.1.1 project in using yesod init. When I run "yesod devel" I get the following error:

yesod: You need to re-run the 'configure' command. The version of Cabal being used has changed (was Cabal-1.10.1.0, now Cabal-1.12.0). Additionally the compiler is different (was ghc-7.0, now ghc-7.2) which is probably the cause of the problem.

I use GHC 7.2.1 Is yesod doing something tricky to get a different version of GHC or do I need to do some more configuration to use GHC 7.2.1 with yesod? If I run the compiled binary it works fine. Is this expected behavior?

I got the same kind of error messages when trying our GHC 7.2 as well. I think it might have to do with the version of Cabal (the library) that cabal (the command line tool) is build against. But I never nailed this down directly.

No, Yesod does not do anything by itself, but you might have multiple installations of GHC and Cabal, for example one global and one user-specific.

I had a similiar problem and posted it on ServerFault (thought it was OT here) but got no answer. I finally solved the issue by a complete reinstallation of the Haskell platform (only one version). Tried everything from updating the cabal-install to updating yesod to configure-command - nothing worked.

Strangest thing: I had some weired path problem: cabal --version showed a old version and only the new one if I was directly in the cabal-bin path ... but there were no other cabal.exe nor installs in my PATH variable that I found ... nasty