Index: head/Mk/Uses/gl.mk
===================================================================
--- head/Mk/Uses/gl.mk	(revision 517001)
+++ head/Mk/Uses/gl.mk	(revision 517002)
@@ -1,55 +1,57 @@
 # $FreeBSD$
 # 
 # Use OpenGL and related libraries and ports
 # 
 # Feature:	gl
 # Usage:	USES=gl
 #		USE_GL=egl gbm gl glesv2 glew glu glut
 #		
 #		USE_GL specifies which GL components to add as dependencies.
 #		Not specifying USE_GL with USES=gl is an error.
 #		USE_GL=yes implies USE_GL=glu.  This is deprecated
 # 
 # MAINTAINER:	x11@FreeBSD.org
 
 .if !defined(_INCLUDE_USES_GL_MK)
 _INCLUDE_USES_GL_MK=yes
 
 _GL_egl_LIB_DEPENDS=		libEGL.so:graphics/mesa-libs
 _GL_gbm_LIB_DEPENDS=		libgbm.so:graphics/mesa-libs
 _GL_gl_LIB_DEPENDS=		libGL.so:graphics/mesa-libs
 _GL_gl_USE_XORG=		xorgproto
 _GL_glesv2_LIB_DEPENDS=		libGLESv2.so:graphics/mesa-libs
 _GL_glew_LIB_DEPENDS=		libGLEW.so:graphics/glew
 _GL_glu_LIB_DEPENDS=		libGLU.so:graphics/libGLU
 _GL_glu_USE_XORG=		xorgproto
 _GL_glut_LIB_DEPENDS=		libglut.so:graphics/freeglut
 
 .if !empty(gl_ARGS)
 IGNORE=	USES=gl takes no arguments
 .endif
 
 .if !defined(USE_GL)
 IGNORE=		need to specify gl component with USE_GL
 .elif ${USE_GL:tl} == yes
 DEV_WARNING+=	"USE_GL=yes is deprecated, please add USE_GL=glu (default) or specify component"
 USE_GL=		glu
 .endif
 
 .for _component in ${USE_GL}
 .if !defined(_GL_${_component}_LIB_DEPENDS)
 IGNORE=		uses unknown GL component
 .else
 USE_XORG+=	${_GL_${_component}_USE_XORG}
 LIB_DEPENDS+=	${_GL_${_component}_LIB_DEPENDS}
 .endif
 .endfor
 
-# We only need USES=xorg if we want USE_XORG modules
+# We only need to include xorg.mk if we want USE_XORG modules
+# USES+=xorg does not provide any functionality, it just silences an error
+# message about USES=xorg not being set
 .if defined(USE_XORG) && !empty(USE_XORG)
 USES+=		xorg
 .include "${USESDIR}/xorg.mk"
 .endif
 
 # _INCLUDE_USES_GL_MK
 .endif
Index: head/Mk/Uses/motif.mk
===================================================================
--- head/Mk/Uses/motif.mk	(revision 517001)
+++ head/Mk/Uses/motif.mk	(revision 517002)
@@ -1,36 +1,38 @@
 # $FreeBSD$
 #
 # handle dependency on motif
 #
 # Feature:	motif
 # Usage:	USES=motif
 #
 # If WANT_LESSTIF is defined in user make.conf then lesstif will be used
 # instead of open-motif
 #
 # MAINTAINER: portmgr@FreeBSD.org
 
 .if !defined(_INCLUDE_USES_MOTIF_MK)
 _INCLUDE_USES_MOTIF_MK=	yes
 
 .if !empty(motif_ARGS)
 IGNORE=	USES=motif takes no arguments
 .endif
 
 .if defined(WANT_LESSTIF)
 LIB_DEPENDS+=		libXm.so:x11-toolkits/lesstif
 .else
 USE_XORG+=	xpm
 LIB_DEPENDS+=		libXm.so.4:x11-toolkits/open-motif
 .endif
 
 MOTIFLIB?=	-L${LOCALBASE}/lib -lXm
 MAKE_ENV+=	MOTIFLIB="${MOTIFLIB}"
 
-# We only need USES=xorg if we want USE_XORG modules
+# We only need to include xorg.mk if we want USE_XORG modules
+# USES+=xorg does not provide any functionality, it just silences an error
+# message about USES=xorg not being set
 .if defined(USE_XORG) && !empty(USE_XORG)
 USES+=		xorg
 .include "${USESDIR}/xorg.mk"
 .endif
 
 .endif
Index: head/Mk/Uses/xorg-cat.mk
===================================================================
--- head/Mk/Uses/xorg-cat.mk	(revision 517001)
+++ head/Mk/Uses/xorg-cat.mk	(revision 517002)
@@ -1,186 +1,188 @@
 # $FreeBSD$
 # 
 # xorg ports categories and other things needed to build xorg ports.
 # This is intended only for ports of xorg and freedesktop.org applications.
 #
 # Use USES=xorg and USE_XORG to depend on various xorg components.
 #
 # Feature:	xorg-cat
 # Usage:	USES=xorg-cat:category[,buildsystem]
 #
 # 		category is one of:
 # 		* app      Installs applications, no shared libraries.
 # 		* data     Installs only data.
 # 		* doc      no particular notes
 # 		* driver   depends on xorgproto at least
 # 		* font     don't install .pc file
 # 		* lib      various dependencies, install .pc file, needs
 # 		           pathfix
 # 		* proto    install .pc file, needs pathfix, most only needed at
 # 		           build time.
 # 		* util     no particular notes
 # 		* xserver  xorg x servers
 #
 # 		These categories has to match upstream categories.  Don't invent
 # 		your own.
 #
 # 		builsystem is one of:
 # 		* autotools (default)
 # 		* meson (experimental)
 #
 #
 # By defining USE_GITLAB and GL_COMMIT, it is possible to pull code straight
 # from the freedesktop.org gitlab, instead of official release tarballs.
 #
 #.MAINTAINER:	x11@FreeBSD.org
 
 .if !defined(_INCLUDE_USES_XORG_CAT_MK)
 _INCLUDE_USES_XORG_CAT_MK=yes
 
 _XORG_CATEGORIES=	app data doc driver font lib proto util xserver
 _XORG_BUILDSYSTEMS=	autotools meson
 
 _XORG_CAT=		# empty
 _XORG_BUILDSYS=		# empty
 
 .  if empty(xorg-cat_ARGS)
 IGNORE=		no arguments specified to xorg-cat
 .  endif
 
 .  for _arg in ${xorg-cat_ARGS}
 .    if ${_XORG_CATEGORIES:M${_arg}}
 .      if empty(_XORG_CAT)
 _XORG_CAT=	${_arg}
 .      else
 IGNORE=		multipe xorg categories specified via xorg-cat:${xorg-cat_ARGS:ts,}
 .      endif
 .    elif ${_XORG_BUILDSYSTEMS:M${_arg}}
 .      if empty(_XORG_BUILDSYS)
 _XORG_BUILDSYS=	${_arg}
 .      else
 IGNORE=		multipe xorg build systems specified via xorg-cat:${xorg-cat_ARGS:ts,}
 .      endif
 .    else
 IGNORE=		unknown argument specified via xorg-cat:${xorg-cat_ARGS:ts,}
 .    endif
 .  endfor
 
 # Default to the autotools build system
 .  if empty(_XORG_BUILDSYS)
 _XORG_BUILDSYS=		autotools
 .  endif
 
 # Default variables, common to all new modular xorg ports.
 .  if empty(USES:Mtar)
 EXTRACT_SUFX?=		.tar.bz2
 .  endif
 
 DIST_SUBDIR=	xorg/${_XORG_CAT}
 
 .  if ${_XORG_BUILDSYS} == meson
 IGNORE=		meson build not supported yet
 .include "${USESDIR}/meson.mk"
 .  elif ${_XORG_BUILDSYS} == autotools
 GNU_CONFIGURE=		yes
 .  else
 # This should not happen
 IGNORE=		unknown build system specified via xorg-cat:${xorg-cat_ARGS:ts,}
 .  endif
 
 .  if defined(USE_GITLAB)
 # Set up things for fetching from freedesktop.org gitlab.
 # This can be overridden using normal GL_* macros in the ports Makefile.
 # We make a best guess for GL_ACCOUNT and GL_PROJECT.
 GL_SITE?=		https://gitlab.freedesktop.org/xorg
 GL_ACCOUNT?=		${_XORG_CAT}
 GL_PROJECT?=		${PORTNAME:tl}
 .    if ${_XORG_BUILDSYS} == meson
 # set up meson stuff here
 .    else
 # Things from GL doesn't come with pre-generated configure, add dependency on
 # autoreconf and run it, if we're using autotools.
 .include "${USESDIR}/autoreconf.mk"
 .    endif
 .  else
 MASTER_SITES?=		XORG/individual/${_XORG_CAT}
 .  endif
 
 #
 ## All xorg ports needs pkgconfig to build, but some ports look for pkgconfig
 ## and then continues the build.
 .include "${USESDIR}/pkgconfig.mk"
 
 #
 ## All xorg ports needs xorg-macros.
 .  if ${PORTNAME} != xorg-macros
 USE_XORG+=      xorg-macros
 .  endif
 
 .  if ${_XORG_CAT} == app
 # Nothing at the moment
 
 .  elif ${_XORG_CAT} == data
 # Nothing at the moment.
 
 .  elif ${_XORG_CAT} == driver
 USE_XORG+=	xi xorg-server xorgproto
 .    if ${_XORG_BUILDSYS} == meson
 # Put special stuff for meson here
 .    else
 CONFIGURE_ENV+=	DRIVER_MAN_SUFFIX=4x DRIVER_MAN_DIR='$$(mandir)/man4'
 libtool_ARGS?=	# empty
 .include "${USESDIR}/libtool.mk"
 INSTALL_TARGET=	install-strip
 .    endif
 
 .  elif ${_XORG_CAT} == font
 FONTNAME?=	${PORTNAME:C/.*-//g:S/type/Type/:S/ttf/TTF/:S/speedo/Speedo/}
 .    if ${_XORG_BUILDSYS} == meson
 # Put special stuff for meson here
 .    else
 CONFIGURE_ARGS+=	--with-fontrootdir=${PREFIX}/share/fonts
 CONFIGURE_ENV+=	FONTROOTDIR=${PREFIX}/share/fonts
 .    endif
 .    if !defined(NOFONT)
 .include "${USESDIR}/fonts.mk"
 BUILD_DEPENDS+=	mkfontscale>=0:x11-fonts/mkfontscale \
 		bdftopcf:x11-fonts/bdftopcf
 PLIST_FILES+=	"@comment ${FONTSDIR}/fonts.dir" \
 		"@comment ${FONTSDIR}/fonts.scale"
 .    endif
 
 .  elif ${_XORG_CAT} == lib
 .include "${USESDIR}/pathfix.mk"
 .    if ${_XORG_BUILDSYS} == meson
 # put meson stuff here
 .    else
 libtool_ARGS?=	# empty
 .include "${USESDIR}/libtool.mk"
 USE_LDCONFIG=	yes
 CONFIGURE_ARGS+=--enable-malloc0returnsnull
 .    endif
 
 .  elif ${_XORG_CAT} == proto
 .include "${USESDIR}/pathfix.mk"
 
 .  elif ${_XORG_CAT} == xserver
 DISTNAME?=	xorg-server-${PORTVERSION}
 .include "${USESDIR}/pathfix.mk"
 .    if ${_XORG_BUILDSYS} == meson
 # put meson stuff here
 .    else
 CONFIGURE_ARGS+=	--with-xkb-path=${LOCALBASE}/share/X11/xkb \
 			--with-fontrootdir=${LOCALBASE}/share/fonts
 .    endif
 LIB_PC_DEPENDS+=	${LOCALBASE}/libdata/pkgconfig/dri.pc:graphics/mesa-dri
 USE_XORG+=	fontutil
 
 .  endif # ${_XORG_CAT} == <category>
 
-# We only need USES=xorg if we want USE_XORG modules
+# We only need to include xorg.mk if we want USE_XORG modules
+# USES+=xorg does not provide any functionality, it just silences an error
+# message about USES=xorg not being set
 .  if defined(USE_XORG) && !empty(USE_XORG)
 USES+=		xorg
 .include "${USESDIR}/xorg.mk"
 .  endif
 
 .endif