I was trying to upgrade to ghc-7.8 the other day, and got this
compilation failure when building ghc-mtl-1.2.1.0 (see the end of the
message).
I'm using the haskell overlay on Gentoo Linux straight out of the box,
no local cabal installations of anything.
Now I was told that other people can
The last time I saw this error, it was because the package database
was messed up (there was an instance of MonadIO in scope, but it
was for the wrong package.) However, I don't know what the source
of the problem is here.
Edward
Excerpts from i hamsa's message of 2014-07-20 08:26:52 +0100:
I
I think I found the problem.
package ghc-7.8.3 requires transformers-0.3.0.0
package mtl-2.2.1 requires transformers-0.4.1.0
package exceptions-0.6.1 requires transformers-0.4.1.0
I wonder how is this ever supposed to work :(
On Sun, Jul 20, 2014 at 9:01 PM, Edward Z. Yang ezy...@mit.edu wrote:
It looks like you will have to install old versions of mtl/exceptions
which work on transformers-0.3.0.0, although undoubtedly the real
problem is that GHC should update what version of transformers it
is distributing.
Edawrd
Excerpts from i hamsa's message of 2014-07-20 19:25:36 +0100:
I think
