before 5.5 configure was doing system checks and defining HAVE_XXX constants accordingly. In 5.5 cmake is doing that. In the process of converting the build system to cmake some of the checks were lost. As a result the code uses HAVE_XXX constants that are never defined by cmake.
This task is about verifying that all HAVE_XXX constants that are used in the code are actually results of some cmake system checks.
Basically, every such constant must be present in config.h.cmake and in configure.cmake.