[Paraview] Required CMake version 3.5

[Ben Boeckel]

On Fri, Jun 24, 2016 at 15:50:45 +0200, Christoph Grüninger wrote:
> I don't think it is a good idea to ask for the latest version. Only developers like us have
> a current version of CMake installed. From already released distributions nobody
> provides CMake 3.5.

My thought here is that building ParaView is much harder than CMake, so
it's not a super high barrier to require a custom-built CMake to build a
custom ParaView build.

> > Though I question the distro update policies surrounding where ParaView
> > is aggressively pushed forward when CMake isn't. CMake is *much* better
> > with its backwards compatibility, but I guess it's down to maintainer
> > style to some extent.
> 
> Sorry, there is a misunderstanding. We provide packages for already released
> distributions. We cannot change the CMake version shipped with them. By
> requesting a too recent version, there won't be updated versions of
> ParaView for users of released openSuses any more.
> I know they can download the binaries you provide or get a more recent
> CMake and compile it themselves. You have to weight your inconveniences
> against the ones of your users.

Ah, so this is more like a PPA? Yeah, I guess overriding the CMake from
those wouldn't be a great thing to recommend.

Talking with Utkarsh, we can move the version down since that's our
actual minimum version. However, if things get added to ParaView's build
that require newer CMake support, bumping the minimum version would not
be a huge blocker.

--Ben