[Haskell-cafe] strange behavior of GHC 7.8.2
Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)
kazu at iij.ad.jp
Mon Jul 7 07:58:31 UTC 2014
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
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.
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