[vtk-developers] VTK module system uplift to CMake 3.0 features

[Marcus D. Hanwell]

On Mon, Mar 2, 2015 at 4:53 PM, David Thompson
<david.thompson at kitware.com> wrote:
> Hi Rob,
>
>> With the move to target based usage requirements will the ability to create external vtk modules still exist, and will they be able to use things such as vtkMPI?
>
> Why would target-based usage requirements prevent external VTK modules?
>
Perhaps because removing/deprecating vtkMPI.cmake etc would change the
build system interface. Traditionally the VTK build system has been
fairly static, and people come to rely on CMake code. Not sure that is
a major consideration at this stage, but it should be considered. I
know we have had a number of people ask about the instantiator CMake
code...

My main objection is that Ubuntu LTS 14.04 has CMake 2.8.12.2, and
that is the most recent LTS (next is out next year I believe). CMake
is reasonably easy to obtain/install locally updated versions, but
LTS/distro CMake versions present an additional barrier. If people
agree it is worth it then we should go with it, but a number of people
tend to use LTS/enterprise versions to simplify upgrade cycles (3.0
was tagged June 10 from the looks of it).

Marcus