On Thu, Apr 23, 2015 at 7:39 PM, Ryan Schmidt wrote:

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On Apr 23, 2015, at 7:23 PM, Peng Yu wrote:

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Long story short: Try $> cabal install --extra-include-dirs=/opt/local/include --extra-lib-dirs=/opt/local/lib

I tried it but it still shows the error messages.

~$ cabal install --extra-include-dirs=/opt/local/include --extra-lib-dirs=/opt/local/lib cabal-install

Resolving dependencies... Configuring cabal-install-1.22.3.0... Failed to install cabal-install-1.22.3.0 Build log ( /Users/py/.cabal/logs/cabal-install-1.22.3.0.log ): cabal: Error: some packages failed to install: cabal-install-1.22.3.0 failed during the configure step. The exception was: user error ('/usr/bin/ghc' exited with an error:

You've installed ghc into /usr/bin? That's probably not a good idea. Prefix /usr is only for the OS vendor to install software into.

This is what installed from the haskell installer. I agree this might not be a good idea. But I have no control over it. -- Regards, Peng