title: ldd show duplicated shared library
body: <p>I have no clear why <code>ldd</code> shows me the same shared library more than once when it cannot find a dependency.
  In a little executable that uses boost, the output is:</p>
  
  <pre><code>libboost_chrono.so.1.49.0 =&gt; not found
  libboost_system.so.1.49.0 =&gt; not found
  libboost_system.so.1.49.0 =&gt; not found
  libboost_program_options.so.1.49.0 =&gt; not found
  libboost_regex.so.1.49.0 =&gt; not found
  </code></pre>
  
  <p>otherwise after installing the correct dependencies ldd shows only one:    </p>
  
  <pre><code>libboost_system.so.1.49.0 =&gt; /usr/lib/libboost_system.so.1.49.0 
  libboost_regex.so.1.49.0 =&gt; /usr/lib/libboost_regex.so.1.49.0 
  libboost_program_options.so.1.49.0 =&gt; /usr/lib/libboost_program_options.so.1.49.0
  libboost_chrono.so.1.49.0 =&gt; /usr/lib/libboost_chrono.so.1.49.0 
  </code></pre>
  
  <p>why does this happen?</p>
  
  <p>Thanks,</p>