diff -up qtbase-everywhere-src-5.12.1/src/gui/Qt5GuiConfigExtras.cmake.in.foo qtbase-everywhere-src-5.12.1/src/gui/Qt5GuiConfigExtras.cmake.in
--- qtbase-everywhere-src-5.12.1/src/gui/Qt5GuiConfigExtras.cmake.in.foo	2019-04-30 15:18:24.886346423 -0500
+++ qtbase-everywhere-src-5.12.1/src/gui/Qt5GuiConfigExtras.cmake.in	2019-04-30 15:19:48.303873296 -0500
@@ -66,8 +66,10 @@ unset(_GL_INCDIRS)
 # Don\'t check for existence of the "_qt5gui_OPENGL_INCLUDE_DIR" because it is
 # optional.
 
+if (NOT ${_qt5gui_OPENGL_INCLUDE_DIR} STREQUAL "/usr/include")
 list(APPEND Qt5Gui_INCLUDE_DIRS ${_qt5gui_OPENGL_INCLUDE_DIR})
 set_property(TARGET Qt5::Gui APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${_qt5gui_OPENGL_INCLUDE_DIR})
+endif()
 
 unset(_qt5gui_OPENGL_INCLUDE_DIR CACHE)