On Sun, May 11, 2014 at 8:58 PM, John Ky <john@gocatch.com> wrote:

I have some code that compiles when running on GHC on OS X, but not on Ubuntu:

No instance for (hashable-1.2.1.0:Data.Hashable.Class.GHashable

(GHC.Generics.Rep Point))
arising from a use of `hashable-1.2.1.0:Data.Hashable.Class.$gdmhashWithSalt'

Possible fix:
add an instance declaration for
(hashable-1.2.1.0:Data.Hashable.Class.GHashable

(GHC.Generics.Rep Point))
In the expression:
(hashable-1.2.1.0:Data.Hashable.Class.$gdmhashWithSalt)

In an equation for `hashWithSalt':
hashWithSalt
= (hashable-1.2.1.0:Data.Hashable.Class.$gdmhashWithSalt)

In the instance declaration for `Hashable Point'

The fully qualified (with package name/version) typeclass makes me think you have multiple versions of the hashable package installed, and the one your source is using is different from one pulled in by something else.

ghc makes it dangerous to have multiple versions of a package installed. Use `ghc-pkg list` to make sure you have only one; if there is one in the global section and another in the local section, remove the local one and reinstall anything broken by that with `cabal install $thepackage --constraint='hashable installed'`.

brandon s allbery kf8nh sine nomine associates

allbery.b@gmail.com ballbery@sinenomine.net

unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net