Weird IDE behavior on MacOS GitHub agent

[ptziegler]

A few days ago, several of our test cases started to fail for seemingly no reason.

For our builds, we use the macos-latest agent, which received an update three days ago and is very likely the culprit:
actions/runner-images#14132

One of the issues, for example, is that the call to PlatformUI.getWorkbench().getDisplay().getActiveShell() now returns null, which to me, indicates that the IDE is no longer launched.

Has anyone with more MacOS expertise seen a problem like that in the past? I've also noticed that the platform tests are still run on the macos-14. Is there are similar reason for that?

[akurtakov]

One good step is to indicate whether a HelloWorls SWT snippet works with the new images so it is known whether it's SWT or smth else.

[Phillipus]

My tests (as commented on eclipse-gef/gef-classic#1123) show that it could be the GH runner that causes the problem not the actual macOS version.

[ptziegler]

I think the mystery has been solved as the GH runner being the culprit, because now a prompt is shown on the runner, which always takes the focus. The same issue can also be seen on the SWT tests now.