On Mon, May 26, 2014 at 3:49 PM, Yitzchak Gale <gale@sefer.org> wrote:

Johan Tibell wrote:
>> I don't know if shipping both Cabal 1.18 and 1.20 in
>> the HP will lead to problems. If so, I can backport

>> the cabal-install changes to 1.18.

Mark Lentczner wrote:
> all's well... Johan back ported the changes

So it's moot for this release. But in principle, what would
have been the problem with having the platform installers
ship with the 1.20 executable, or build the 1.20 executable
in a sandbox for installers that build it, and then still ship
with Cabal-1.18. in the libraries?

I don't think it's a problem, two different version of a package can happily coexist in a package DB after all. There's a theoretical diamond dependency problem if some other package in HP links against Cabal.

I mostly backported the change to be conservative, as I couldn't foresee all possible issues.