Re: [Haskell-cafe] Building a Haskell project which depends on an old version of base

On Tue, Feb 14, 2012 at 3:53 PM, Rogan Creswick wrote:

On Tue, Feb 14, 2012 at 12:14 PM, Steven J. Murdoch wrote:

...

$ ghc-pkg list base /Users/ghc6/homebrew/Cellar/ghc/6.12.3/lib/ghc/package.conf.d   base-3.0.3.2   base-4.2.0.2

I'm a bit fuzzy on the details when it comes to the core packages that are distributed with ghc, but my understanding is that the compiler is /very/ needy about which base it can use.  As far as I know, the only way to change versions of Base is by changing the compiler to the version that uses the desired base.

With that in mind, having two base libraries installed in the same package database seems like a recipe for disaster.

GHC 6.12.1 shipped with two versions of base, so this is okay in this case. But I really don't know if we export two different versions of GHC.* from the different versions of base. Antoine