title: Release build does not work - error with Eigen library?
body: <p>When I build my program in debug mode, everything works fine. However, when I switch to release build, I get the following errors. It seems that there is a problem with <code>Eigen</code>. Could anyone please help?</p>
  
  <pre><code>1&gt;------ Build started: Project: qtdemo, Configuration: Release Win32 ------
  1&gt;  moc_qtdemo.cpp
  1&gt;c:\users\documents\visual studio 2012\projects\qtdemo\qtdemo\generatedfiles\release\../../qtdemo.h(6): fatal error C1083: Cannot open include file: 'Eigen/Dense': No such file or directory
  1&gt;  main.cpp
  1&gt;c:\users\documents\visual studio 2012\projects\qtdemo\qtdemo\qtdemo.h(6): fatal error C1083: Cannot open include file: 'Eigen/Dense': No such file or directory
  1&gt;  qtdemo.cpp
  1&gt;c:\users\documents\visual studio 2012\projects\qtdemo\qtdemo\qtdemo.h(6): fatal error C1083: Cannot open include file: 'Eigen/Dense': No such file or directory
  1&gt;  Generating Code...
  ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
  </code></pre>