Re: [Haskell-cafe] Re: problem with cabal for syb-with-class

thank you very much for the explanation! i take that in this case, the error is in the cabal, which does not list the required package. andrew On Tue, 2008-08-26 at 15:09 +0100, Duncan Coutts wrote:

On Tue, 2008-08-26 at 14:30 +0100, Dougal Stanton wrote:

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On Tue, Aug 26, 2008 at 2:22 PM, Duncan Coutts wrote:

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So when ghc finds that one of your modules needs to import something that is not in one of the given packages it says that it's in another package that is 'hidden'. Of course it's only hidden because Cabal told ghc to hide them.

Yes, it is one of those unfortunate error messages that says "I know what the problem is *and* how to fix it, but I'm not going to". ;-)

Actually it's more like: "I know what the problem is but I cannot fix it. He knows how to fix it, but doesn't know there's a problem!" :-)

GHC knows what the problem is but it's just following orders. Cabal gave the orders but doesn't know there is a problem.

That's why it'll be fixed when Cabal does the dep chasing rather than delegating that to ghc --make. Cabal will then be able to either just pull in the (probably) right packages, or report the problem using the language of the problem domain and not the implementation.

Duncan