Re: [Haskell-cafe] Bad interface problem.

But why it does not occur on other installation? And Albert, I did not directly install QuickCheck. It was required by yesod. On Wed, Jul 11, 2012 at 10:55 PM, Brandon Allbery wrote:

On Wed, Jul 11, 2012 at 5:28 AM, Magicloud Magiclouds wrote:

...

Even I removed all user space packages, the error was still. I think it is a ghc pkg problem, that every package register itself as package:function while ghc (or cabal?) required package-version:function.

That's not the problem, it's the symptom. Package symbols are always versioned; ghc only shows the version when it's the only way to disambiguate symbols.

So when it shows you a conflict where one is versioned and the other isn't, you have multiple versions of a package installed.

...

But --constraint='template-haskell-2.7.0.0' did make it compiled.

And that's how you prevent it.

-- brandon s allbery allbery.b@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms

-- 竹密岂妨流水过 山高哪阻野云飞 And for G+, please use magiclouds#gmail.com.