Due to popular demant into each port which might be inserted into dependency

list by bsd.port.mk insert anti foot-shooting device, which prevents
infinite fork loop when the user defines corresponding USE_XXX in global
make.conf, command line or environment.

Similar devices should probably be inserted into ports that might be inserted
into dependency list by others bsd.foo.mk files (bsd.ruby.mk, bsd.python.mk
and so on.)

47 files changed, 188 insertions, 2 deletions

diff --git a/archivers/bzip2/Makefile b/archivers/bzip2/Makefile
index c1928f39c43f..04d2fe27dbe7 100644
--- a/archivers/bzip2/Makefile
+++ b/archivers/bzip2/Makefile
@@ -27,6 +27,10 @@ MLINKS=		bzip2.1 bunzip2.1   bzip2.1 bzcat.1   bzip2.1 bz2cat.1 \
 		bzgrep.1 bzfgrep.1 \
 		bzmore.1 bzless.1
 
+.ifdef USE_BZIP2
+.error You have `USE_BZIP2' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 do-install:
 	${INSTALL_PROGRAM} ${WRKSRC}/bzip2 ${PREFIX}/bin
 	${LN} -sf ${PREFIX}/bin/bzip2 ${PREFIX}/bin/bunzip2
diff --git a/archivers/unzip/Makefile b/archivers/unzip/Makefile
index 767294ce728c..dcbd2ce1a7d7 100644
--- a/archivers/unzip/Makefile
+++ b/archivers/unzip/Makefile
@@ -25,6 +25,10 @@ EXTRACT_ONLY=   ${PORTNAME}550.tar.gz
 MAKE_ENV=       LOCAL_UNZIP="${CFLAGS} -DUSE_UNSHRINK -DUSE_SMITH_CODE"
 .endif
 
+.ifdef USE_UNZIP
+.error You have `USE_UNZIP' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if ${ARCH} == "i386"
diff --git a/devel/autoconf213/Makefile b/devel/autoconf213/Makefile
index 600cafb0e211..051ace52e0e9 100644
--- a/devel/autoconf213/Makefile
+++ b/devel/autoconf213/Makefile
@@ -28,6 +28,10 @@ CONFIGURE_ENV=	M4=${LOCALBASE}/bin/gm4
 CONFIGURE_ARGS=	--program-suffix=213 --datadir=${PREFIX}/share/autoconf213
 WRKSRC=		${WRKDIR}/autoconf
 
+.if defined(USE_AUTOCONF) || defined(USE_AUTOCONF_VER)
+.error You have `USE_AUTOCONF' or `USE_AUTOCONF_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-patch:
 	@-${RM} ${WRKSRC}/*.info*
 
diff --git a/devel/automake/Makefile b/devel/automake/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake/Makefile
+++ b/devel/automake/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake110/Makefile b/devel/automake110/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake110/Makefile
+++ b/devel/automake110/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake14/Makefile b/devel/automake14/Makefile
index e447b7379256..3333ebc8f75f 100644
--- a/devel/automake14/Makefile
+++ b/devel/automake14/Makefile
@@ -23,6 +23,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-patch:
 	@-${RM} ${WRKSRC}/*.info* ${WRKSRC}/*.dvi
 	${MV} ${WRKSRC}/automake.texi ${WRKSRC}/automake14.texi
diff --git a/devel/automake15/Makefile b/devel/automake15/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake15/Makefile
+++ b/devel/automake15/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake16/Makefile b/devel/automake16/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake16/Makefile
+++ b/devel/automake16/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake17/Makefile b/devel/automake17/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake17/Makefile
+++ b/devel/automake17/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake18/Makefile b/devel/automake18/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake18/Makefile
+++ b/devel/automake18/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/automake19/Makefile b/devel/automake19/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/automake19/Makefile
+++ b/devel/automake19/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/bison-devel/Makefile b/devel/bison-devel/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison-devel/Makefile
+++ b/devel/bison-devel/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/bison/Makefile b/devel/bison/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison/Makefile
+++ b/devel/bison/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/bison175/Makefile b/devel/bison175/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison175/Makefile
+++ b/devel/bison175/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/bison1875/Makefile b/devel/bison1875/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison1875/Makefile
+++ b/devel/bison1875/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/bison2/Makefile b/devel/bison2/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison2/Makefile
+++ b/devel/bison2/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/bison20/Makefile b/devel/bison20/Makefile
index f9c118fa8644..ed700d39c92e 100644
--- a/devel/bison20/Makefile
+++ b/devel/bison20/Makefile
@@ -27,6 +27,10 @@ CONFIGURE_TARGET=	--target=${MACHINE_ARCH}-unknown-freebsd${OSREL}
 
 MAN1=		bison.1
 
+.ifdef USE_BISON
+.error You have `USE_BISON' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-extract:
 	@${RM} -f ${WRKSRC}/doc/bison.info*
 
diff --git a/devel/gmake/Makefile b/devel/gmake/Makefile
index 5c90eb5e6ab1..ce8d5b070e51 100644
--- a/devel/gmake/Makefile
+++ b/devel/gmake/Makefile
@@ -23,6 +23,10 @@ CONFIGURE_ENV=	CPPFLAGS="-I${LOCALBASE}/include -DHAVE_LOCALE_H -DHAVE_LC_MESSAG
 
 MAN1=		gmake.1
 
+.ifdef USE_GMAKE
+.error You have `USE_GMAKE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 # joerg@freebsd.org says our getloadavg() no longer requires setgid kmem
 
 post-install:
diff --git a/devel/gmake381/Makefile b/devel/gmake381/Makefile
index 5c90eb5e6ab1..ce8d5b070e51 100644
--- a/devel/gmake381/Makefile
+++ b/devel/gmake381/Makefile
@@ -23,6 +23,10 @@ CONFIGURE_ENV=	CPPFLAGS="-I${LOCALBASE}/include -DHAVE_LOCALE_H -DHAVE_LC_MESSAG
 
 MAN1=		gmake.1
 
+.ifdef USE_GMAKE
+.error You have `USE_GMAKE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 # joerg@freebsd.org says our getloadavg() no longer requires setgid kmem
 
 post-install:
diff --git a/devel/gnu-automake/Makefile b/devel/gnu-automake/Makefile
index 6bdf74a777bd..a63c7ea3d63d 100644
--- a/devel/gnu-automake/Makefile
+++ b/devel/gnu-automake/Makefile
@@ -21,6 +21,10 @@ WRKSRC=		${WRKDIR}/${DISTNAME}
 
 STRIP=		# none
 
+.if defined(USE_AUTOMAKE) || defined(USE_AUTOMAKE_VER)
+.error You have `USE_AUTOMAKE' or `USE_AUTOMAKE_VER' variables defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-configure:
 	${PERL} -pi -e "s^%%X11BASE%%^${X11BASE}^" ${WRKSRC}/aclocal.in
 
diff --git a/devel/gnu-libtool/Makefile b/devel/gnu-libtool/Makefile
index 1a27412f5338..a2ee543ab5ee 100644
--- a/devel/gnu-libtool/Makefile
+++ b/devel/gnu-libtool/Makefile
@@ -22,4 +22,8 @@ INSTALLS_SHLIB=	yes
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV=	PREFIX=${PREFIX}
 
+.ifdef USE_LIBTOOL
+.error You have `USE_LIBTOOL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.mk>
diff --git a/devel/imake-4/Makefile b/devel/imake-4/Makefile
index ff68bc6c4182..3c650db988cb 100644
--- a/devel/imake-4/Makefile
+++ b/devel/imake-4/Makefile
@@ -22,6 +22,10 @@ MAINTAINER=	anholt@freebsd.org
 PREFIX?=	${X11BASE}
 USE_PERL5=	YES
 
+.ifdef USE_IMAKE
+.error You have `USE_IMAKE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if ${OSVERSION} < 500000
diff --git a/devel/imake/Makefile b/devel/imake/Makefile
index 71f86452ab44..beb091ee45a9 100644
--- a/devel/imake/Makefile
+++ b/devel/imake/Makefile
@@ -35,6 +35,10 @@ MANCOMPRESSED=	yes
 INSTALL_TARGET=	install install.man
 MTREE_FILE=	/etc/mtree/BSD.x11.dist
 
+.ifdef USE_IMAKE
+.error You have `USE_IMAKE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 do-configure:
 	@${ECHO_CMD} > ${WRKSRC}/cf/host.def
 	@(cd ${WRKDIR}/xc; \
diff --git a/devel/libtool/Makefile b/devel/libtool/Makefile
index 1a27412f5338..a2ee543ab5ee 100644
--- a/devel/libtool/Makefile
+++ b/devel/libtool/Makefile
@@ -22,4 +22,8 @@ INSTALLS_SHLIB=	yes
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV=	PREFIX=${PREFIX}
 
+.ifdef USE_LIBTOOL
+.error You have `USE_LIBTOOL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.mk>
diff --git a/devel/libtool13/Makefile b/devel/libtool13/Makefile
index 1a27412f5338..a2ee543ab5ee 100644
--- a/devel/libtool13/Makefile
+++ b/devel/libtool13/Makefile
@@ -22,4 +22,8 @@ INSTALLS_SHLIB=	yes
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV=	PREFIX=${PREFIX}
 
+.ifdef USE_LIBTOOL
+.error You have `USE_LIBTOOL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.mk>
diff --git a/devel/libtool14/Makefile b/devel/libtool14/Makefile
index 1a27412f5338..a2ee543ab5ee 100644
--- a/devel/libtool14/Makefile
+++ b/devel/libtool14/Makefile
@@ -22,4 +22,8 @@ INSTALLS_SHLIB=	yes
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV=	PREFIX=${PREFIX}
 
+.ifdef USE_LIBTOOL
+.error You have `USE_LIBTOOL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.mk>
diff --git a/devel/libtool15/Makefile b/devel/libtool15/Makefile
index 1a27412f5338..a2ee543ab5ee 100644
--- a/devel/libtool15/Makefile
+++ b/devel/libtool15/Makefile
@@ -22,4 +22,8 @@ INSTALLS_SHLIB=	yes
 GNU_CONFIGURE=	yes
 CONFIGURE_ENV=	PREFIX=${PREFIX}
 
+.ifdef USE_LIBTOOL
+.error You have `USE_LIBTOOL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.mk>
diff --git a/emulators/linux_base-8/Makefile b/emulators/linux_base-8/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base-8/Makefile
+++ b/emulators/linux_base-8/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/emulators/linux_base-rh-9/Makefile b/emulators/linux_base-rh-9/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base-rh-9/Makefile
+++ b/emulators/linux_base-rh-9/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/emulators/linux_base-suse-9.1/Makefile b/emulators/linux_base-suse-9.1/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base-suse-9.1/Makefile
+++ b/emulators/linux_base-suse-9.1/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/emulators/linux_base-suse-9.2/Makefile b/emulators/linux_base-suse-9.2/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base-suse-9.2/Makefile
+++ b/emulators/linux_base-suse-9.2/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/emulators/linux_base-suse-9.3/Makefile b/emulators/linux_base-suse-9.3/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base-suse-9.3/Makefile
+++ b/emulators/linux_base-suse-9.3/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/emulators/linux_base/Makefile b/emulators/linux_base/Makefile
index 8cb25cc99b19..a3fd42bada52 100644
--- a/emulators/linux_base/Makefile
+++ b/emulators/linux_base/Makefile
@@ -63,6 +63,10 @@ UPDATES=		glibc-common-2.2.4-29.${MACHINE_ARCH}.rpm \
 				glibc-2.2.4-29.${MACHINE_ARCH}.rpm \
 				zlib-1.1.3-25.7.${MACHINE_ARCH}.rpm
 
+.ifdef USE_LINUX
+.error You have `USE_LINUX' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if (${MACHINE_ARCH} == "i386")
diff --git a/graphics/Mesa3/Makefile b/graphics/Mesa3/Makefile
index a8200a941dbe..1e392a66c048 100644
--- a/graphics/Mesa3/Makefile
+++ b/graphics/Mesa3/Makefile
@@ -53,6 +53,10 @@ MAKE_ARGS=	-e
 MAKE_ENV+=	SUB_GL="${SUB_GL}"		\
 		INCLUDE_GL=${INCLUDE_GL}
 
+.ifdef USE_MESA
+.error You have `USE_MESA' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-patch:
 	@${REINPLACE_CMD} -e 's|-lpthread|${PTHREAD_LIBS}|g' ${WRKSRC}/configure
 
diff --git a/graphics/mesagl/Makefile b/graphics/mesagl/Makefile
index a8200a941dbe..1e392a66c048 100644
--- a/graphics/mesagl/Makefile
+++ b/graphics/mesagl/Makefile
@@ -53,6 +53,10 @@ MAKE_ARGS=	-e
 MAKE_ENV+=	SUB_GL="${SUB_GL}"		\
 		INCLUDE_GL=${INCLUDE_GL}
 
+.ifdef USE_MESA
+.error You have `USE_MESA' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-patch:
 	@${REINPLACE_CMD} -e 's|-lpthread|${PTHREAD_LIBS}|g' ${WRKSRC}/configure
 
diff --git a/graphics/xpm/Makefile b/graphics/xpm/Makefile
index 75e75820c880..664258448671 100644
--- a/graphics/xpm/Makefile
+++ b/graphics/xpm/Makefile
@@ -18,6 +18,10 @@ INSTALLS_SHLIB=	yes
 
 MAN1=		cxpm.1 sxpm.1
 
+.ifdef USE_XPM
+.error You have `USE_XPM' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 post-install:
 	@ranlib ${PREFIX}/lib/libXpm.a
 
diff --git a/lang/gcc295/Makefile b/lang/gcc295/Makefile
index b6f8482a3a80..afc8c93d76ab 100644
--- a/lang/gcc295/Makefile
+++ b/lang/gcc295/Makefile
@@ -21,6 +21,10 @@ USE_BZIP2=	yes
 
 LATEST_LINK=	gcc295
 
+.ifdef USE_GCC
+.error You have `USE_GCC' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 GCC_REV=	${DISTNAME:S/gcc-//g:S/.test3//g}
diff --git a/lang/gcc31/Makefile b/lang/gcc31/Makefile
index 0b92fb1c433e..630eac1230de 100644
--- a/lang/gcc31/Makefile
+++ b/lang/gcc31/Makefile
@@ -79,6 +79,10 @@ MAN1=		cpp31.1 g++31.1 g77-31.1 gcc31.1 gcov31.1 \
 		jcf-dump31.1 jv-scan31.1 jv-convert.1
 MAN7=		fsf-funding.7 gfdl.7 gpl.7
 
+.ifdef USE_GCC
+.error You have `USE_GCC' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-fetch:
 	@${ECHO} "Making GCC ${DISTNAME:S/^gcc-//} for ${OPSYS} ${OSREL} ${PORTOBJFORMAT}	target ${CONFIGURE_TARGET}"
 
diff --git a/lang/perl5.6/Makefile b/lang/perl5.6/Makefile
index 943341d19ed3..d88341c43852 100644
--- a/lang/perl5.6/Makefile
+++ b/lang/perl5.6/Makefile
@@ -50,6 +50,10 @@ CONFIGURE_ARGS+=	-Dusemymalloc=n
 
 INCLUDEDIR=	/usr/include
 
+.ifdef USE_PERL5
+.error You have `USE_PERL5' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 MAN1=	a2p.1 c2ph.1 dprofpp.1 find2perl.1 h2ph.1 h2xs.1 perl.1 \
diff --git a/lang/perl5/Makefile b/lang/perl5/Makefile
index 943341d19ed3..d88341c43852 100644
--- a/lang/perl5/Makefile
+++ b/lang/perl5/Makefile
@@ -50,6 +50,10 @@ CONFIGURE_ARGS+=	-Dusemymalloc=n
 
 INCLUDEDIR=	/usr/include
 
+.ifdef USE_PERL5
+.error You have `USE_PERL5' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 MAN1=	a2p.1 c2ph.1 dprofpp.1 find2perl.1 h2ph.1 h2xs.1 perl.1 \
diff --git a/print/freetype/Makefile b/print/freetype/Makefile
index 280a86efcaf7..d5a83380046f 100644
--- a/print/freetype/Makefile
+++ b/print/freetype/Makefile
@@ -24,6 +24,10 @@ USE_LIBTOOL=	yes
 INSTALLS_SHLIB=	yes
 CONFIGURE_ARGS=	--disable-nls --enable-static --enable-shared
 
+.ifdef USE_FREETYPE
+.error You have `USE_FREETYPE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 # Older versions of freetype installed include files in ${PREFIX}/include
 # this is a compatibility hack for now
 
diff --git a/security/openssl/Makefile b/security/openssl/Makefile
index 175444a02ffc..315b1ba4feeb 100644
--- a/security/openssl/Makefile
+++ b/security/openssl/Makefile
@@ -15,6 +15,10 @@ MASTER_SITES=	http://www.openssl.org/source/ \
 
 MAINTAINER=	dinoex@FreeBSD.org
 
+.ifdef USE_OPENSSL
+.error You have `USE_OPENSSL' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if ${PORTOBJFORMAT} == "aout"
diff --git a/textproc/sed_inplace/Makefile b/textproc/sed_inplace/Makefile
index 4494303348ce..df905fc56dba 100644
--- a/textproc/sed_inplace/Makefile
+++ b/textproc/sed_inplace/Makefile
@@ -18,6 +18,10 @@ NO_WRKSUBDIR=	yes
 MAKEFILE=	${PKGDIR}/src/Makefile
 MAKE_ENV=	PKGDIR="${PKGDIR}"
 
+.ifdef USE_REINPLACE
+.error You have `USE_REINPLACE' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if ${OSVERSION} > 500033
diff --git a/x11-toolkits/open-motif/Makefile b/x11-toolkits/open-motif/Makefile
index 35f2126ed57e..5f308789a4ad 100644
--- a/x11-toolkits/open-motif/Makefile
+++ b/x11-toolkits/open-motif/Makefile
@@ -28,6 +28,10 @@ INSTALLS_SHLIB=	yes
 
 DEMOS_SRC=	${WRKSRC}/demos/programs
 
+.ifdef USE_MOTIF
+.error You have `USE_MOTIF' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 .if ${XFREE86_VERSION} >= 4
diff --git a/x11/XFree86-4-libraries/Makefile b/x11/XFree86-4-libraries/Makefile
index 7ba9227c93d6..8fb1cdccdd12 100644
--- a/x11/XFree86-4-libraries/Makefile
+++ b/x11/XFree86-4-libraries/Makefile
@@ -74,6 +74,10 @@ ForceNormalLib?=	DEFAULT
 DebuggableLibraries?=	DEFAULT
 # End of XFree86 User Config
 
+.ifdef USE_XLIB
+.error You have `USE_XLIB' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .include <bsd.port.pre.mk>
 
 # BuildXF86DRI is false for FreeBSD < 4.1
diff --git a/x11/XFree86/Makefile b/x11/XFree86/Makefile
index cbc499ea8719..60c6cb50d758 100644
--- a/x11/XFree86/Makefile
+++ b/x11/XFree86/Makefile
@@ -44,6 +44,10 @@ PLIST=		${PKGDIR}/pkg-plist.pc98
 PLIST=		${PKGDIR}/pkg-plist.alpha
 .endif
 
+.ifdef USE_XLIB
+.error You have `USE_XLIB' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 .if defined(XDM_DES) && (${USA_RESIDENT} != YES && ${USA_RESIDENT} != NO)
 pre-fetch:
 	@${ECHO}
diff --git a/x11/dgs/Makefile b/x11/dgs/Makefile
index 3811835380a7..036afd4507dd 100644
--- a/x11/dgs/Makefile
+++ b/x11/dgs/Makefile
@@ -28,10 +28,12 @@ GNU_CONFIGURE=	yes
 MAN1=		dgs.1 dpsnx.agent.1
 MANN=		dpsexec.man makepsres.man xepsf.man
 
+.ifdef USE_DGS
+.error You have `USE_DGS' variable defined either in environment or in make(1) arguments. Please undefine and try again.
+.endif
+
 pre-patch:
 	@find ${WRKSRC} -name "Makefile.in" | xargs ${PERL} -pi -e \
 		's|manm|mann|g'
 
-
-
 .include <bsd.port.mk>