[CMake] CMake unit tests and the enable_testing() macro

[Zé]

I'm test-driving CMake for a new project I've just started and I'm 
currently trying to set up a unit test framework.  The project is a 
dynamic library written in C++, the unit tests are based on Boost test, 
and the project tree is organized essentially as follows:

.
├── CMakeLists.txt
├── mylibrary
│   ├── CMakeLists.txt
│   └── sample.c++
└── unit_tests
     ├── CMakeLists.txt
     └── test_sample.c++



I believe that I've managed to get things up and running, but in the 
process I've stumbled on an issue.

Apparently, if I call the enable_testing() macro within 
${Project}/unit_tests/CMakeLists.txt, calling make test does nothing, 
and the following error message is shown:

     make: *** No rule to make target `test'.  Stop.


Yet, if enable_testing() is called from ${Project}/CMakeLists.txt, 
calling make test runs as expected.

Am I missing something?



Thanks