[CMake] BUILD_INTERFACE genex used even in install(EXPORT...

[Stephen Kelly]

Mueller-Roemer, Johannes Sebastian wrote:

> produces a file containing:
> IMPORTED_LINK_INTERFACE_LIBRARIES_RELEASE
> "${Boost_COROUTINE_LIBRARY_RELEASE}"

You need to make sure policy CMP0022 is NEW for the 
BUILD_INTERFACE to be handled correctly. Unfortunately 
there is no warning in this case.

See 

 http://www.cmake.org/cmake/help/v3.1/manual/cmake-policies.7.html

for more.

Thanks,

Steve.