[Haskell-cafe] Fwd: hackage compile failure with QuickCheck 2.5

[Erik Hesselink]

On Wed, Jul 18, 2012 at 11:29 AM, Ross Paterson <ross at soi.city.ac.uk> wrote:
> On Wed, Jul 18, 2012 at 09:35:52AM +0100, Erik Hesselink wrote:
>> I don't think you can install this package on 7.4. As Andres said, it
>> requires containers 0.5, but ghc 7.4's base libraries (in this case,
>> template-haskell) use containers 0.4, and can't be reinstalled. I
>> guess your best bet is to use sbv-2.1, which depends on containers >=
>> 0.3, or to unpack it and see if you can loosen the containers
>> dependency and see if it still works with 0.4
>
> I'm talking about unattended automated builds, so tweaking isn't an
> option.  On the other hand breaking the package environment isn't so bad,
> because I'm throwing it away after each build.

We use --force-reinstalls for automated builds as well, inside a
cabal-dev sandbox. I think that flag is a fine default for such
situations.

>> So in short, no combination of flags will work in this case, I think.
>> Failure is the best option.
>
> Actually --force-reinstalls does work in this case, and this thread began
> with Levent being unhappy with the failure option for his package, so
> I'm tempted to use that flag on all hackage builds.

Does that mean that you *can* reinstall template-haskell? I didn't know that...

Erik