In JDK-8169285, we enabled SWT tests. This however led to a problem on MacOS. They are therefore disabled on MacOS as of now.

When running the tests, the following warning is printed, with an exception right after: "***WARNING: Display must be created on main thread due to Cocoa restrictions. Use vmarg -XstartOnFirstThread."

It might be possible that adding this flag to the gradle test jvmArgs will fix this problem.