Part of log:
...
kBuild: Linking VBoxPython
kBuild: Installing VBoxPython => /usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/bin/VBoxPython.so
kBuild: Compiling VBoxRemPrimary - /usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/VBoxRecompiler.c
cc1: error: to generate dependencies you must specify either -M or -MM
kmk: *** [/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary/VBoxRecompiler.o] Error 1
The failing command:
@gcc48 -c -O2 -g -pipe -Wall -Wextra -Wno-missing-field-initializers -Wno-unused -Wno-trigraphs -fdiagnostics-show-option -Wno-unused-parameter -Wno-long-long -Wno-long-long -Werror-implicit-function-declaration -Wno-variadic-macros -O2 -mtune=generic -fno-omit-frame-pointer -fno-strict-aliasing -fvisibility=hidden -DVBOX_HAVE_VISIBILITY_HIDDEN -DRT_USE_VISIBILITY_DEFAULT -fPIC -Wno-sign-compare -Werror-implicit-function-declaration -m64 -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/Sun/crt -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/Sun -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/target-i386 -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/tcg -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/fpu -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/VBox/VMM/include -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/tcg/i386 -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler -I/usr/local/include -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary/dtrace -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/include -I/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release -DVBOX -DVBOX_OSE -DVBOX_WITH_64_BITS_GUESTS -DVBOX_WITH_DEBUGGER -DRT_OS_FREEBSD -D__FREEBSD__ -DRT_ARCH_AMD64 -D__AMD64__ -DVBOX_WITH_HARDENING -DRTPATH_APP_PRIVATE=\"/usr/local/share/virtualbox-ose\" -DRTPATH_APP_PRIVATE_ARCH=\"/usr/local/lib/virtualbox\" -DRTPATH_SHARED_LIBS=\"/usr/local/lib/virtualbox\" -DRTPATH_APP_DOCS=\"/usr/local/share/doc/virtualbox-ose\" -DIN_RING3 -DHC_ARCH_BITS=64 -DGC_ARCH_BITS=64 -DPIC -DIN_REM_R3 -DREM_INCLUDE_CPU_H -DNEED_CPU_H -DVBOX_WITH_RAW_MODE -DVBOX_WITH_RAW_RING1 -DLOG_USE_C99 -D_BSD -D__x86_64__ -Wp,-MD,/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary/VBoxRecompiler.o.dep -Wp,-MT,/usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary/VBoxRecompiler.o -Wp,-MP -o /usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/out/freebsd.amd64/release/obj/VBoxRemPrimary/VBoxRecompiler.o /usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.3.38/src/recompiler/VBoxRecompiler.c
*** Error code 2

Stop.
make[1]: stopped in /usr/ports/emulators/virtualbox-ose
*** Error code 1

Stop.
make: stopped in /usr/ports/emulators/virtualbox-ose
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade20160510-38596-3r9clj env UPGRADE_TOOL=portupgrade UPGRADE_PORT=virtualbox-ose-4.3.38 UPGRADE_PORT_VER=4.3.38 make
** Fix the problem and try again.
** Listing the failed packages (-:ignored / *:skipped / !:failed)
	! emulators/virtualbox-ose (virtualbox-ose-4.3.38)	(unknown build error)
root@vladiom:~ # 


<uname>
FreeBSD 10.3-RELEASE-p2 amd64

<make.conf>
CPUTYPE?=core2
OPTIONS_SET=CUPS
WITHOUT_LPR=YES
DEFAULT_VERSIONS=apache=2.4
QT4_OPTIONS=CUPS NAS QGTKSTYLE
LOCALIZED_LANG=ru
DEFAULT_VERSIONS+=perl5=5.20
MAKE_JOBS_UNSAFE=yes
DEFAULT_VERSIONS=mysql=5.7
.if ${.CURDIR:M*/ports/devel/ccache}
NO_CCACHE=yes
.endif