We are developing a plugin which runs fine on IJ 14 in headless mode but crashes on IJ 15 when
ProjectUtil.openProject(projectPath, null, false);
is called. When debugging we see that com.intellij.notification.EventLog.ProjectTracker is not loaded by the class loader even though it is in the same jar (idea.jar) as the calling class (com.intellij.openapi.components.impl.ComponentManagerImpl#registerComponents).
To clarify running the plugin against an IntelliJ Platform Plugin SDK home path that points to an IJ 14 installation works whereas one pointing to IJ 15 does not. We can call the headless plugin from either IJ 14 or IJ 15 but the home path is what changes the outcome.
Does anyone have any hints on how to fix the plugin for 15? I'm happy to share more information if that will be useful.