title: Qt 5.12: Failed to find "GL/gl.h" in "/usr/include/libdrm"
body: <p>I have a freshly installed <code>Ubuntu 18.04.3</code> system (NVIDIA) with only <code>Qt SDK 5.12.5</code>, <code>build-essential</code>, <code>git</code>, and <code>CMake</code> installed. I'm trying to build a Qt project by opening the main CMakeLists.txt in Qt Creator:</p>
  
  <pre><code>Check for working CXX compiler: /usr/bin/g++
  Check for working CXX compiler: /usr/bin/g++ -- works
  Detecting CXX compiler ABI info
  Detecting CXX compiler ABI info - done
  Detecting CXX compile features
  Detecting CXX compile features - done
  CMake Error at /home/juzzlin/Qt/5.12.5/gcc_64/lib/cmake/Qt5Gui/Qt5GuiConfigExtras.cmake:9 (message):
    Failed to find "GL/gl.h" in "/usr/include/libdrm".
  Call Stack (most recent call first):
    /home/juzzlin/Qt/5.12.5/gcc_64/lib/cmake/Qt5Gui/Qt5GuiConfig.cmake:174 (include)
    /home/juzzlin/Qt/5.12.5/gcc_64/lib/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake:89 (find_package)
    CMakeLists.txt:89 (find_package)
  </code></pre>
  
  <p>What should I still install?</p>
  
  <p>Note: I haven't installed Qt from repositories at all. Only via the official online installer.</p>