title: Using External Library (libarchive) in Qt - No .lib file
body: <p>I've built libarchive on both Linux and Windows following the build instructions.</p>
  
  <p>Basically I have some .a files and a dll, but no .lib file. I want to link my Qt project to this library, but all of the examples I have seen require a .lib file, but there doesn't seem to be one.</p>
  
  <p>This is what my .pro contains:</p>
  
  <pre><code>LIBS += -L$$PWD/libarchive/lib/ -llibarchive
  
  INCLUDEPATH += $$PWD/libarchive/include
  DEPENDPATH += $$PWD/libarchive/include
  </code></pre>
  
  <p>and my code is:</p>
  
  <pre><code>#include &lt;QtGui/QApplication&gt;
  #include &lt;archive.h&gt;
  #include &lt;archive_entry.h&gt;
  
  int main(int argc, char *argv[]) {
      QApplication app(argc, argv);
  
      struct archive *a;
      a = archive_read_new();
  
      return app.exec();
  }
  </code></pre>
  
  <p>The headers are found, the project builds, but dies as soon as I try to run it.</p>