[CMake] find_package with config file always set xyz_FOUND to true?

[Anton Deguet]

Hello,

I am trying to use the following syntax:
find_package (xyz REQUIRED xyz1 xyz2) using a config file, i.e. NOT Findxyz.cmake.

I have a file named xyz-config.cmake that contains some code to check if the required components are available or not (based on how xyz was compiled).  Ideally I would like the find_package command to set xyz_FOUND to false if:
- xyz-config.cmake file is not found (that's working by default)
OR
- xyz-config.cmake file is found BUT one or more component is missing

In my xyz-config.cmake, I tried:
- set (xyz_FOUND FALSE)  # overall package not found as required
- set (xyz2_FOUND FALSE)  # component not found, hoping find_package would compare this to the list xyz_FIND_COMPONENTS

But in all cases, it seems that find_package resets xyz_FOUND to 1 as long as the file xyz-config.cmake is found.  Is there a way to set xyz_FOUND to 0 within xyz-config.cmake?

Anton