Problem compiling emulators/virtualbox-ose-kmod 4.1.8_2

[Mike Clarke]

portmaster -a fails with:

cc -O -pipe -march=athlon-mp -DRT_OS_FREEBSD -DIN_RING0 -DIN_RT_R0 -DIN_SUP_R0 -DVBOX -DRT_WITH_VBOX -w -DVBOX_WITH_HARDENING -DVBOX_WITH_64_BITS_GUESTS -DRT_ARCH_X86 -Werror -D_KERNEL -DKLD_MODULE -nostdinc  -Iinclude -I. -Ir0drv -I. -I@ -I@/contrib/altq -finline-limit=8000 --param 
inline-unit-growth=100 --param 
large-function-growth=1000 -fno-common  -mno-align-long-strings -mpreferred-stack-boundary=2  -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -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 -c /data1/tmp/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-4.1.8_OSE/out/freebsd.x86/release/bin/src/vboxdrv/r0drv/freebsd/memobj-r0drv-freebsd.c
/data1/tmp/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-4.1.8_OSE/out/freebsd.x86/release/bin/src/vboxdrv/r0drv/freebsd/memobj-r0drv-freebsd.c: 
In function 'rtR0MemObjFreeBSDAllocPhysPages':
/data1/tmp/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-4.1.8_OSE/out/freebsd.x86/release/bin/src/vboxdrv/r0drv/freebsd/memobj-r0drv-freebsd.c:405: 
error: invalid type argument of '->'
*** Error code 1

Stop 
in /data1/tmp/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-4.1.8_OSE/out/freebsd.x86/release/bin/src/vboxdrv.

I ran portsnap immediately before portmaster so my ports are up to date.

Any suggestions?

-- 
Mike Clarke