In several places, preprocessor definition checks mention "#error [X] already defined, re-configure with UNITTEST_ENABLE_SHORT_MACROS set to 0 and use UNITTEST_[X] instead".

It seems like this refers to some earlier implementation and UNITTEST_DISABLE_SHORT_MACROS should be defined in UnitTest++/Config.h instead.

However, enabling this definition in the config file breaks basically all the tests (in the tests/ directory).

This is also easily circumvented by telling CMake to not include the tests in the makefile.
However, I would expect that changing the configuration settings according to its own explanation should not result in build failures. Otherwise, I would expect a mention of this limitation in the README.