Specifying CMake options for external CMake project

Hi! I'd like to use the following to wrap a CMake-native project in a catkin environment by exporting the build_type as cmake: (Code preview on GitHub issue: https://github.com/ros/catkin/issues/1007) While this works great to build, it defaults all options as in the CMake project. In many cases, we'd like to set a few of those - e.g., not to build tests etc. (what we would usually do by cmake .. -DBUILD_TESTS=OFF). Is there a way to do this, or a convenient work-around? Thanks, Wolfgang