root:/usr/ports/print/acroreadwrapper# make
===>  License check disabled, port has not defined LICENSE
===>  Extracting for acroreadwrapper-0.0.20110529
=> SHA256 Checksum OK for linux_adobe_kmod-20110529.tar.gz.
===>  Patching for acroreadwrapper-0.0.20110529
===>  Configuring for acroreadwrapper-0.0.20110529
===>  Building for acroreadwrapper-0.0.20110529
Warning: Object directory not changed from original /usr/ports/print/acroreadwrapper/work/linux_adobe_kmod-20110529
@ -> /usr/src/sys
machine -> /usr/src/sys/amd64/include
x86 -> /usr/src/sys/x86/include
cc -O2 -fno-strict-aliasing -pipe -march=native -DCOMPAT_FREEBSD32 -DCOMPAT_LINUX32 -Werror -D_KERNEL -DKLD_MODULE -nostdinc   -I. -I@ -I@/contrib/altq -finline-limit=8000 --param inline-unit-growth=100 --param large-function-growth=1000 -fno-common  -fno-omit-frame-pointer  -mno-sse -mcmodel=kernel -mno-red-zone -mno-mmx -msoft-float  -fno-asynchronous-unwind-tables -ffreestanding -fstack-protector -std=iso9899:1999 -fstack-protector -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes  -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef -Wno-pointer-sign -fformat-extensions  -Wmissing-include-dirs -fdiagnostics-show-option -c linux_adobe.c
cc1: warnings being treated as errors
linux_adobe.c: In function 'linux_adobe_linux_sched_setscheduler':
linux_adobe.c:88: warning: implicit declaration of function 'sched_setscheduler'
linux_adobe.c:88: warning: nested extern declaration of 'sched_setscheduler' [-Wnested-externs]
*** Error code 1

Stop in /usr/ports/print/acroreadwrapper/work/linux_adobe_kmod-20110529.
*** Error code 1

Stop in /usr/ports/print/acroreadwrapper.

root:/usr/ports/print/acroreadwrapper# grep -r -- '-Werror' .
./work/linux_adobe_kmod-20110529/@/arm/conf/DB-78XXX:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/arm/conf/DB-88F5XXX:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/arm/conf/DB-88F6XXX:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/arm/conf/DOCKSTAR:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/arm/conf/SHEEVAPLUG:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/arm/conf/TS7800:makeoptions	WERROR="-Werror"
./work/linux_adobe_kmod-20110529/@/boot/arm/at91/Makefile.inc:	-Werror \
./work/linux_adobe_kmod-20110529/@/boot/arm/ixp425/Makefile.inc:	-Werror \
./work/linux_adobe_kmod-20110529/@/conf/kern.pre.mk:WERROR?= -Werror
./work/linux_adobe_kmod-20110529/@/conf/kmod.mk:WERROR?=	-Werror
./work/linux_adobe_kmod-20110529/@/netinet/ipfw/test/Makefile:CFLAGS = -I.. -I. -Wall -Werror -O3 -DIPFW