I think we can do this without warnings in the output logs or
modifications to the project CMakeLists.txt. We can preload
BUILD_TESTING into the cache:

$ cat cache.txt
set(BUILD_TESTING OFF CACHE BOOL "Build the testing tree.")

This is a neat trick!

Did you check whether this also overwrites any default in CMakeList.txt? Otherwise we might need to pass `-DBUILD_TESTING=…` on the command line, too.

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |