title: Android IllegalArgumentException: already added
body: <p>I have created an android application that uses <code>android-support-v4.jar</code>.
  Now when I add an android library to this project I get this error when building:</p>
  
  <pre><code>UNEXPECTED TOP-LEVEL EXCEPTION:
  java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
  [2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1
  </code></pre>
  
  <p>The library I'm trying to add is Facebook SDK, which also happens to use android-support-v4.jar.
  Only solution for this error I found was removing library from one of build paths, but I can't do it - all options all disabled when I select this jar.</p>
  
  <p>Here is full error trace:</p>
  
  <pre><code>UNEXPECTED TOP-LEVEL EXCEPTION:
  java.lang.IllegalArgumentException: already added: Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoIcsImpl;
      at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:123)
      at com.android.dx.dex.file.DexFile.add(DexFile.java:163)
      at com.android.dx.command.dexer.Main.processClass(Main.java:486)
      at com.android.dx.command.dexer.Main.processFileBytes(Main.java:455)
      at com.android.dx.command.dexer.Main.access$400(Main.java:67)
      at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:394)
      at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:245)
      at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:131)
      at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:109)
      at com.android.dx.command.dexer.Main.processOne(Main.java:418)
      at com.android.dx.command.dexer.Main.processAllFiles(Main.java:329)
      at com.android.dx.command.dexer.Main.run(Main.java:206)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at com.android.ide.eclipse.adt.internal.build.DexWrapper.run(DexWrapper.java:180)
      at com.android.ide.eclipse.adt.internal.build.BuildHelper.executeDx(BuildHelper.java:703)
      at com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.build(PostCompilerBuilder.java:577)
      at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:728)
      at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
      at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:199)
      at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:321)
      at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:396)
      at org.eclipse.core.internal.resources.Project$1.run(Project.java:618)
      at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
      at org.eclipse.core.internal.resources.Project.internalBuild(Project.java:597)
      at org.eclipse.core.internal.resources.Project.build(Project.java:124)
      at com.android.ide.eclipse.adt.internal.project.ProjectHelper.doFullIncrementalDebugBuild(ProjectHelper.java:1000)
      at com.android.ide.eclipse.adt.internal.launch.LaunchConfigDelegate.launch(LaunchConfigDelegate.java:147)
      at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:855)
      at org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:704)
      at org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:1047)
      at org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1251)
      at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
  [2012-11-08 16:02:31 - ShoppingApp Android] Dx 1 error; aborting
  [2012-11-08 16:02:31 - ShoppingApp Android] Conversion to Dalvik format failed with error 1
  </code></pre>