module 'free-4.6.1:Main' is defined in multiple files

Mateusz Kowalczyk fuuzetsu at
Mon Mar 24 21:33:44 UTC 2014

On 24/03/14 21:26, Mikhail Glushenkov wrote:
> Hi,
> On 24 March 2014 18:54, Mateusz Kowalczyk <fuuzetsu at> wrote:
>> PS: How does one go about downgrading Cabal and cabal-install? If we
>> wanted to check whether cabal is the problem, how?
> You can force the Cabal lib version to use (in case you have multiple
> versions installed) with 'install --cabal-lib-version'. To downgrade
> cabal-install itself to some older version you need to compile and
> install that version.

About cabal-install, I'm mostly concerned about not breaking my whole
existing system by installing an old version. Are there any steps I can
take to retain sane setup? I don't have an OSX machine and I can't
exactly ask people volunteering to break their Haskell environments.

Are there any catches to having multiple Cabal libs installed or will
the latest one always be used if not specified?

Mateusz K.

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