CPPFLAGS_GTKGLEXT ?= $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --cflags $(STDERR_TO_DEVNULL))
LIBS_GTKGLEXT ?= $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --libs-only-L $(STDERR_TO_DEVNULL)) \
$(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --libs-only-l $(STDERR_TO_DEVNULL))
CPPFLAGS_GTKGLEXT ?= $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --cflags $(STDERR_TO_DEVNULL))
LIBS_GTKGLEXT ?= $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --libs-only-L $(STDERR_TO_DEVNULL)) \
$(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) $(PKGCONFIG) gtkglext-1.0 --libs-only-l $(STDERR_TO_DEVNULL))