Users too often burn themselves when enabling this flag globally.
Gentoo-bug: 554478, 584010, 585334, 588914, 627758, 629632
--- /dev/null
+# Copyright 1999-2017 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+# USE=gles2 in the following packages disables full OpenGL
+# Upstream does not test for that case and packages frequently
+# fail to build or run if set.
+dev-python/PyQt5 gles2
+dev-qt/qt3d gles2
+dev-qt/qtdatavis3d gles2
+dev-qt/qtdeclarative gles2
+dev-qt/qtgui gles2
+dev-qt/qtmultimedia gles2
+dev-qt/qtopengl gles2
+dev-qt/qtprintsupport gles2
+dev-qt/qtwidgets gles2
+kde-apps/kdenlive gles2
+kde-frameworks/plasma gles2
+kde-plasma/kinfocenter gles2
+kde-plasma/kwin gles2