Upgrading Stack to Cabal 2.2

[Mikhail Glushenkov]

Hi,

On 20 February 2018 at 13:47, Michael Snoyman <michael at snoyman.com> wrote:
> Hi all,
>
> Oleg mentioned to me on Reddit that a 2.2 branch has been cut for Cabal, and
> recommended we try to upgrade Stack to it. I'm sharing information here on
> that process in case it's useful to others, either as feedback on the API
> changes, or help for others going through similar upgrades. If anyone would
> rather that I do or do not post such reports in the future, let me know.
>
> [...]

Thanks for sharing this, I've updated the 2.2 migration guide [1] with
some of the things you mentioned that weren't already in the guide.
Good point about the SPDX changelog entry as well, I'll make sure that
this change is documented better before the release.

I'll keep the point about `allBuildInfos` in mind. I agree that for
the library user it's normally better to get a compile error when
there's a backwards-incompatible change, but, as Herbert & Oleg
correctly note, from the API design standpoint it can be a bit of a
balancing act.


[1] https://github.com/haskell/cabal/wiki/2.2-migration-guide