[CMake] Why does INTERFACE type targets only support whitelisted properties?

[Stephen Kelly]

Taylor Braun-Jones wrote:

> Consider library project Foo that uses a header-only project Bar. In
> FooConfig.cmake, it is a important to ensure any projects using Foo also
> use the exact same version of Bar that Foo was originally built with

COMPATIBLE_INTERFACE_STRING and similar properties are designed for that use 
case. 

You would populate an INTERFACE_ property on the INTERFACE target, which is 
whitelisted already:

 https://cmake.org/cmake/help/v3.4/manual/cmake-buildsystem.7.html#compatible-interface-properties

 http://article.gmane.org/gmane.comp.programming.tools.cmake.devel/5813

Thanks,

Steve.