[Dune] first release candidate for 2.6 release

[Christian Engwer]

On Wed, Jan 03, 2018 at 02:49:02PM +0100, Markus Blatt wrote:
> On Wed, Jan 03, 2018 at 02:37:25PM +0100, Markus Blatt wrote:
> 
> > > * dune-functions requires CMake 2.8.12. Dune common 2.6 will require
> > > CMake 3.1.
> >
> 
> Here is the complete picture of the requirements:
> 
> dune-alugrid/CMakeLists.txt:cmake_minimum_required(VERSION 2.8.12)
> dune-common/CMakeLists.txt:cmake_minimum_required(VERSION 3.1)
> dune-geometry/CMakeLists.txt:cmake_minimum_required(VERSION 2.8.12)
> dune-grid/CMakeLists.txt:cmake_minimum_required(VERSION 2.8.12)
> dune-istl/CMakeLists.txt:cmake_minimum_required(VERSION 2.8.12)
> dune-localfunctions/CMakeLists.txt:cmake_minimum_required(VERSION
> 2.8.12)
> dune-python/CMakeLists.txt:cmake_minimum_required(VERSION 3.1)
> dune-uggrid/CMakeLists.txt:cmake_minimum_required(VERSION 2.8.12)
> 
> Markus

apparently dune-common bumped the requirements, but I can't find a
commit that would actually require the change, except for

commit bcf85fe4aef2edaefecbfe8f4eb626606c93826a (refs/merge-requests/323/head, refs/keep-around/bcf85fe4aef2edaefecbfe8f4eb626606c93826a)
Author: Christoph Grüninger <gruenich at dune-project.org>
Date:   Thu Sep 28 23:42:00 2017 +0200

    [CMake] Drop backported code from CMake 3.1

which just removed compatibility code.

Sure, it is better to rely on upstream code, but I agree, that it
would not have done much harm to stick to 2.8.12. The situation might
be different for dune-python, but this should not be an argument for
the core modules.

Best
Christian