That conversation is fresh, as in ongoing!. The suggested use of CATKIN_ENABLE_TESTING is how I currently use the more CMake-y (or CTest-y?) BUILD_TESTING. I don't understand the internals enough to justify having a catkin-specific variable. I presume "things" must be done under the hood depending on the value of this variable that can't be done with a more generic one like BUILD_TESTING.

I'm largely ignorant of all things catkin. That's what you get for staying with a mostly rosbuild distro for so long...