How to synchronize test execution in parallel multi-project builds?

Does Gradle provide a way to specify a mutual exclusive lock on Java test execution for some of the projects in our multi-project build? We need to run the JUnit tests in these projects sequentially because these projects are all testing against an external server (but each project with its own configuration).

This counts for just 5 out of 150 projects in our build. For the other projects we would like to have the parallelization in place to speed things up.

just noticed that the suggestion for introducing a mutex on tasks has been reported 13 days ago, see: