I use unison to synchronize work environments between different workstations (more convenient than rsync IMO), and include the eclipse workspace in the synchronized directory. The problem is sometimes, if the remote eclipse is running, sync will corrupt some workspace state that prevents Eclipse from running. This happens to me every 2-3 months.
Eclipse displays an error message to look at eclipse-workspace/.metadata/.log, which contains something like:
!ENTRY org.eclipse.osgi 4 0 2015-10-16 10:10:41.245
!MESSAGE Application error
!STACK 1
java.lang.NoClassDefFoundError: org/eclipse/core/resources/IContainer
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:140)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:669)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:608)
at org.eclipse.equinox.launcher.Main.run(Main.java:1515)
at org.eclipse.equinox.launcher.Main.main(Main.java:1488)
Caused by: java.lang.ClassNotFoundException: An error occurred while automatically activating bundle org.eclipse.core.resources (107).
at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:116)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(ClasspathManager.java:531)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(ModuleClassLoader.java:324)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:327)
at org.eclipse.osgi.internal.loader.sources.SingleSourcePackage.loadClass(SingleSourcePackage.java:36)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:398)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:352)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:344)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 14 more
Caused by: org.osgi.framework.BundleException: Exception in org.eclipse.core.resources.ResourcesPlugin.start() of bundle org.eclipse.core.resources.
at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:792)
at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:721)
at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:941)
at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:318)
at org.eclipse.osgi.container.Module.doStart(Module.java:571)
at org.eclipse.osgi.container.Module.start(Module.java:439)
at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:454)
at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:107)
... 23 more
A solution that has worked for me previously (found online) is removing *.snap in eclipse-workspace/.metadata/.plugins/org.eclipse.core.resources:
rm eclipse-workspace/.metadata/.plugins/org.eclipse.core.resources/*.snap
Some times I had to re-import the projects into the workspace, but otherwise worked fine.
If you’re here you’ve probably had similar problems.. Good luck and hope this helps!