title: Running .NET Core nuget package with native dependencies, library not found
body: <p>I have these added to my project.</p>
  
  <pre><code>&lt;Content Include="../../native/medxdcmtk/lib/libmedxdcmtk.so"&gt;
    &lt;PackagePath&gt;runtimes/debian-x64/native/libmedxdcmtk.so&lt;/PackagePath&gt;
    &lt;Pack&gt;true&lt;/Pack&gt;
  &lt;/Content&gt;
  &lt;Content Include="../../native/dcmtk/lib/libdcmtk.so.10"&gt;
    &lt;PackagePath&gt;runtimes/debian-x64/native/libdcmtk.so.10&lt;/PackagePath&gt;
    &lt;Pack&gt;true&lt;/Pack&gt;
  &lt;/Content&gt;
  &lt;Content Include="../../native/medxdcmtk/lib/libmedxdcmtk.so"&gt;
    &lt;PackagePath&gt;runtimes/ubuntu-x64/native/libmedxdcmtk.so&lt;/PackagePath&gt;
    &lt;Pack&gt;true&lt;/Pack&gt;
  &lt;/Content&gt;
  &lt;Content Include="../../native/dcmtk/lib/libdcmtk.so.10"&gt;
    &lt;PackagePath&gt;runtimes/ubuntu-x64/native/libdcmtk.so.10&lt;/PackagePath&gt;
    &lt;Pack&gt;true&lt;/Pack&gt;
  &lt;/Content&gt;
  </code></pre>
  
  <p>The resulting package looks like:</p>
  
  <p><a href="https://i.stack.imgur.com/nzRvw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nzRvw.png" alt="nupkg"></a></p>
  
  <p>When I call a method that uses <code>PInvoke</code>, I get this:</p>
  
  <pre><code>Error Message:
   System.DllNotFoundException : Unable to load DLL 'libmedxdcmtk': The specified module could not be found.
   (Exception from HRESULT: 0x8007007E)
  </code></pre>
  
  <p>This happens on both ubuntu and debian (64bit). If I copy the <code>.so</code> files directly to <code>/usr/lib</code>, it works.</p>
  
  <p>Why aren't my native assemblies being located?</p>