[vtkusers] Problem depending on VTK >= 8.1 with CMake 3.12.1 and VTK 8.1.1 on Win 10/MSVC 2017

[Elvis Stansvik]

Hey all,

In the past it was worked for us to depend on VTK 8.1 with

    find_package(VTK 8.1 ....)

But now I'm having trouble with a setup like this:

    - Windows 10
    - CMake 3.12.1
    - VTK 8.1.1

The error I get when configuring our project is:

-- Selecting Windows SDK version 10.0.17134.0 to target Windows 10.0.16299.
CMake Error at CMakeLists.txt:29 (find_package):
  Could not find a configuration file for package "VTK" that is compatible
  with requested version "8.1".

  The following configuration files were considered but not accepted:

    C:/Users/Elvis/Dev/VTK-8.1.1-inst/lib/cmake/vtk-8.1/VTKConfig.cmake,
version: 8.1.1 (64bit)

This is nonsensical to me. Version 8.1.1 (which was found) should be
able to satisfy 8.1.

Just to test, I set the dependency in our CMakeLists.txt to exactly
8.1.1, and got:

-- Selecting Windows SDK version 10.0.17134.0 to target Windows 10.0.16299.
CMake Error at CMakeLists.txt:29 (find_package):
  Could not find a configuration file for package "VTK" that is compatible
  with requested version "8.1.1".

  The following configuration files were considered but not accepted:

    C:/Users/Elvis/Dev/VTK-8.1.1-inst/lib/cmake/vtk-8.1/VTKConfig.cmake,
version: 8.1.1 (64bit)

Which makes it obvious something is not right.

For reference, cmake was invoked like

    cmake -DCMAKE_PREFIX_PATH=C:/Users/Elvis/Dev/qwt-6.1.2-inst;C:/Users/Elvis/Dev/VTK-8.1.1-inst;C:/Users/Elvis/Dev/HDF5/1.10.2;C:/Users/Elvis/Dev/karchive-5.36.0-inst
..

where C:/Users/Elvis/Dev/VTK-8.1.1-inst is the installation prefix of VTK.

Any ideas? Was there some change in CMake recently that could have caused this?

Many thanks in advance,
Elvis