title: Symbol lookup error (linux - c++)
body: <p>i'm working on multi-agent system like <code>Robocup soccerrSim2d</code> On Gnu-linux .
  My distb is Ubuntu 11.10(kernel 3.2 - gcc 4.6 )</p>
  
  <p>I installed <a href="http://sourceforge.jp/projects/rctools/downloads/51941/librcsc-4.1.0.tar.gz/" rel="nofollow">librcsc</a> from source . (it compiled and installed successfully)</p>
  
  <p>then I installed <a href="http://sourceforge.jp/projects/rctools/downloads/51943/agent2d-3.1.0.tar.gz/" rel="nofollow">agent2d</a> from src . (it compiled and installed successfully too !)</p>
  
  <p>But there is a problem with running the agent2d code : (when I run <code>src/start.sh</code> : )</p>
  
  <p>this Error happens :</p>
  
  <blockquote>
    <p>./src/sample_player: symbol lookup error:
    /usr/local/lib/librcsc_agent.so.7: undefined symbol:
    _ZN4rcsc9UDPSocketC1EPKci</p>
  </blockquote>
  
  <p>What do you think about it guys? Actually, when does "Symbol lookup Error " happen?</p>