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

Hi, On 24 March 2014 22:33, Mateusz Kowalczyk wrote:

On 24/03/14 21:26, Mikhail Glushenkov wrote:

...

Hi,

On 24 March 2014 18:54, Mateusz Kowalczyk 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.

Use a sandbox to compile the cabal-install executable: $ cd cabal/cabal-install $ cabal sandbox init $ cabal sandbox add-source ../Cabal $ cabal install --dependencies-only && cabal build And then copy it to somewhere in PATH: $ cp dist/build/cabal/cabal ~/bin/cabal-1.18

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

Yes, the latest one is always used.