Compiling Qt 5, getting warning "The build will most likely fail."

Question

I'm following this tutorial on compiling Qt 5 on Windows, using Visual Studio 2008 as the compiler.

When running configure.bat I get a warning - The build will most likely fail.

This is the complete command:

configure -developer-build -opensource -nomake examples -nomake tests

This is an excerpt of configure.bat's output:

Running configuration tests...
WARNING: The DirectX SDK could not be detected:
  There is no Direct X SDK installed or the environment variable "DXSDK_DIR" is
not set.
Disabling the ANGLE backend.

WARNING: Using OpenGL ES 2.0 without ANGLE.
Specify -opengl desktop to use Open GL.
The build will most likely fail.

What should I do to avoid this warning? Should I specify -opengl, or should I install Direct X SDK?

Edit

The build (I ran nmake) did fail complaining that GLES2/gl2.h is missing:

c:\workspace\qt5source\qt5\qtbase\include\qtgui\../../src/gui/opengl/qopengl.h(82) : fatal error C1083: Cannot open include file: 'GLES2/gl2.h': No such file or directory

Answer 1

OpenGL ES is a cut down version of the OpenGL specification aimed at smartphones and tablets, ANGLE provides the ability for OpenGL ES API calls to be converted to DirectX equivalents.

Unless you plan on creating apps that target OpenGL ES platforms and Windows, just go with passing -opengl desktop to configure. Otherwise you will need to get hold of the DirectX SDK to enable ANGLE support.