AutoTest: CMake based tests are recognized but failed to run

I have a cmake based project and one subdirectory specifies gtest based unit tests. The autotest plugin of QtCreator 4.2.1 lists all the test cases and allows me to run my tests and get a well formed list of test results.
Trying the same with QtCreator 4.3 beta1 (nightly snapshot #969) failed: I see my test cases in the test view but running them result in the message "FATAL: Could not find command "". ()"

(But I can execute and debug the unittest binary from QtCreator, just running the tests from the test view fails).