title: Fatal error: gst/gst.h: No such file or directory (using CMake)
body: <p>I'm trying to build a C++ application with gstreamer using CMake. In my CMakeLists.txt file, gstreamer is included with the following lines:</p>
  
  <pre><code>find_package(PkgConfig REQUIRED)
  
  pkg_search_module(GST REQUIRED gstreamer-1.0&gt;=1.4
      gstreamer-sdp-1.0&gt;=1.4
      gstreamer-video-1.0&gt;=1.4
      gstreamer-app-1.0&gt;=1.4)
  </code></pre>
  
  <p>I can run <code>cmake</code> without any errors, but <code>make</code> gives the following error:</p>
  
  <blockquote>
    <p>fatal error: gst/gst.h: No such file or directory</p>
  </blockquote>
  
  <p>Gstreamer is installed and I have checked that the gst.h file is located at <em>/usr/include/gstreamer-1.0/gst/gst.h</em> along with the other gstreamer header files.</p>
  
  <p>The following environment variables has been set:</p>
  
  <pre><code>export PKG_CONFIG_PATH=/opt/qt-5.9.1/lib/pkgconfig
  export LD_LIBRARY_PATH=/opt/qt-5.9.1/lib
  export GST_PLUGIN_PATH=/usr/include/gstreamer-1.0
  </code></pre>
  
  <p>I've also checked the output from pkg-config, suggested in another post with similar problem:</p>
  
  <pre><code>$ pkg-config --cflags gstreamer-1.0
  -pthread -I/usr/include/gstreamer-1.0 -I/usr/lib/x86_64-linux-gnu/gstreamer-1.0/include -I/usr/include/glib-2.0 -I/usr/x86_64-linux-gnu/glib-2.0/include
  </code></pre>
  
  <p>So why can't the gstreamer header file be found?</p>
  
  <p>(I'm new to both gstreamer and CMake)</p>