qualified imports, PVP and so on

[Michael Snoyman]

On Wed, Feb 26, 2014 at 2:45 PM, Johan Tibell <johan.tibell at gmail.com>wrote:

> On Wed, Feb 26, 2014 at 1:09 PM, Michael Snoyman <michael at snoyman.com>wrote:
>
>> * The bounds will never help cabal choose a better build plan.
>>
>
> It won't help cabal but it might inform the user what's wrong so he/she
> can do something about it. Dependency errors are more high-level than
> compilation errors.
>
>
>> * The bounds make it very difficult to check and debug new versions of
>> GHC.
>>
>
> I believe we added a cabal flag to skip the upper bounds check. Mikhail,
> do you remember?
>
>

Even with that flag, we'd still have a bit of a problem. It would be nice
if cabal could ignore an upper bound on template-haskell, but respect an
upper bound on some other package that *can* be installed with a newer GHC.
Perhaps adding that flexibility to cabal would be possible.


>  * Including the bounds if you know the build will fail makes for more
>> user-friendly messages.
>>
>
> I think the more friendly message for base is: this package doesn't work
> with this (new) version of GHC. We sometimes have breaking base changes
> (like in the upcoming 7.8 release, which changes some primops.) Having an
> error on the base version is better than a compilation error in that case.
>
>
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