[Haskell-beginners] Quickcheck2 - writing a modifier for test data
nathan.huesken at posteo.de
Sun Mar 31 13:13:18 CEST 2013
That was it.
On 03/31/2013 12:30 PM, Brent Yorgey wrote:
> On Sun, Mar 31, 2013 at 12:21:48PM +0200, Nathan Hüsken wrote:
>> No instance for (QuickCheck-2.4.2:Test.QuickCheck.Arbitrary.Arbitrary
> The fact that it actually lists the package and version number in the
> error message strongly suggests that the problem is conflicting
> versions of the QuickCheck package. Do 'ghc-pkg list QuickCheck' to
> see if you have multiple versions installed, and unregister all but
> one of them.
> Beginners mailing list
> Beginners at haskell.org
More information about the Beginners