Christiaan, Thank you for your reply.
I think GHC always picks the package with the highest version number, and does _not_ resolve to the package that gives the least amount of type errors. The "Loading package transformers-0.3.0.0" is not there due to your own use of transformers. It's being loaded because it is a dependency of 'ghc-7.8.2'.
I have reached the same conclusion. "-v" reveals this: ---- % ghci -v A.hs -package ghc ... hiding package transformers-0.3.0.0 to avoid conflict with later version transformers-0.4.1.0 ... ----
Also note that this behaviour is not specific to 7.8.*, it is also present in 7.6.3. The only thing you can to with both version of transformers installed is to just do:
ghci -package ghc -hide-package transformers-0.4.1.0 A.hs
Thanks. "ghci A.hs -package ghc -package transformers-0.3.0.0" works for me. --Kazu