Subject:   -20- When I compile my Inventor program, I get an error in
                SoDebugError.h.
Date: 30 Apr 1994 15:45:00 CDT

  You, or something you #include, are #include'ing the IRIS GL header
  file (gl/gl.h). It does: "#define WARNING 2", which conflicts with
  the enum value called "WARNING" in SoDebugError. You cannot mix Open
  Inventor with IRIS GL anyway (because you cannot mix OpenGL with IRIS
  GL), so you should fix your program so it doesn't try to #include
  <gl/gl.h> it should use <GL/gl.h> the OpenGL include file.