[Haskell-cafe] strange behavior of GHC 7.8.2

[Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)]

Hi Yuras,

Thank you for your reply.

> I'm 90% sure you have MonadIO and RWST imported from different versions of
> transformers. Try to load the code into ghci and check ':i MonadIO' and ':i
> RWST'. If you'll see fully qualified (including package name and version)
> names somewhere, then that is the issue.
> See also
> http://stackoverflow.com/questions/11068272/acid-state-monadstate-instance-for-update

Yes. Probably MonadIO belongs to transformers 0.3.0.0 while RWST does
to transformers 0.4.1.0.

My question is why this happens. I think that GHCi should use RWST
provided by transformers 0.3.0.0.

--Kazu