http://xyst.i2p/howto_runnerargs.html
How to pass extra arguments to the regression test runner in cmake To configure how ctest executes regression tests, the following cmake variables cam be used: RUNNER, which sets the parallel/serial test runner, used to run regression tests by ctest, default: charmrun RUNNER_NCPUS_ARG, the argument used to specify the number of processors for the test runner, default: +p , RUNNER_ARGS, which enables passing extra arguments to the parallel/serial test runner, default: "" ,...