Undefined symbols for architecture armv7: "_OBJC_CLASS_$_MPMusicPlayerController"
<pre><code>Undefined symbols for architecture armv7:
</code></pre>

<blockquote>
  <p>"_OBJC_CLASS_$_MPMusicPlayerController", referenced from:
        objc-class-ref in liblibPDRCore.a(PGDeviceStatus.o)
      ld: symbol(s) not found for architecture armv7    clang: error: linker command failed with exit code 1 (use -v to see invocation)</p>
</blockquote>

<p>One of my lib was manually dragged into project before now I have it installed by cocoapods ,then the problem occurred. And I tried add the <code>MediaPlayer.framework</code>(although I don't need this framework before) to my project,the problem becomes this : ld: 14 duplicate symbols for architecture armv7</p>

<p>Anyone can help me ?</p>