I've looked at https://answers.ros.org/question/115526/is-test_depend-actually-used-for-anything/ but my question is different.

We have a package A which depends on package B only during testing. When I use "testdepends" tag around package B in my package.xml for package A, it is always built. I cannot find a way to enforce that colcon does not build tests. Note here that -DBUILD_TESTING=OFF does not work as this is only enforcing things at the individual package level, not at the colcon level. *How do I get colcon to not build package B when package B is specified in package A with a "testdepends" tag?*