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

[Antoine Latter]

On Tue, Feb 14, 2012 at 3:53 PM, Rogan Creswick <creswick at gmail.com> wrote:
> On Tue, Feb 14, 2012 at 12:14 PM, Steven J. Murdoch
> <Steven.Murdoch at cl.cam.ac.uk> 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