title: getting "no repository found at..." error when placing my plugin into Eclipse's dropins directory
body: <p>i am using eclipse 3.5 to create a simple plugin bearing an extension point. i built it using headless pde build via ant. the plugin functions properly. i then proceeded to test its extension point by placing my plugin jar into eclipse_home/dropins with intention of eventually creating an extension. but after i start eclipse, i get the following error in its log:</p>
  
  <pre><code>!ENTRY org.eclipse.equinox.p2.core 4 0 2012-03-22 01:00:45.270
  !MESSAGE Provisioning exception
  !STACK 1
  org.eclipse.equinox.internal.provisional.p2.core.ProvisionException: No repository found at file:/C:/eclipse35/dropins/MyPlugin/.
      at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.fail(AbstractRepositoryManager.java:380)
      at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:641)
      at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:92)
      at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:88)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.loadMetadataRepository(Activator.java:90)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.DropinsRepositoryListener.getMetadataRepository(DropinsRepositoryListener.java:184)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.DropinsRepositoryListener.addRepository(DropinsRepositoryListener.java:79)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.DropinsRepositoryListener.added(DropinsRepositoryListener.java:57)
      at org.eclipse.equinox.internal.provisional.p2.directorywatcher.DirectoryWatcher.processFile(DirectoryWatcher.java:200)
      at org.eclipse.equinox.internal.provisional.p2.directorywatcher.DirectoryWatcher.scanDirectories(DirectoryWatcher.java:161)
      at org.eclipse.equinox.internal.provisional.p2.directorywatcher.DirectoryWatcher.poll(DirectoryWatcher.java:108)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.watchDropins(Activator.java:491)
      at org.eclipse.equinox.internal.p2.reconciler.dropins.Activator.start(Activator.java:167)
      at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:782)
      at java.security.AccessController.doPrivileged(Native Method)
      at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:773)
      at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:754)
      at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:352)
      at org.eclipse.osgi.framework.internal.core.AbstractBundle.resume(AbstractBundle.java:370)
      at org.eclipse.osgi.framework.internal.core.Framework.resumeBundle(Framework.java:1068)
      at org.eclipse.osgi.framework.internal.core.StartLevelManager.resumeBundles(StartLevelManager.java:557)
      at org.eclipse.osgi.framework.internal.core.StartLevelManager.incFWSL(StartLevelManager.java:464)
      at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:248)
      at org.eclipse.osgi.framework.internal.core.StartLevelManager.dispatchEvent(StartLevelManager.java:445)
      at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:220)
      at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:330)
  </code></pre>
  
  <p>i have tried both just placing the plugin jar directly in the dropins directory, as well as using the following directory structure: eclipse_home/dropins/MyPlugin/plugins/myplugin.jar. both approaches work just fine with 3rd party plugins, but not with mine. please let me know what i am doing wrong. thank you!</p>