Hello,
the log helps much to identify the issue...
On Thu, Apr 20, 2017 at 12:54:30PM +0000, Janardhan wrote:
make run/virtualbox
[...]
Library-description file libc.mk is missing Library-description file libm.mk is missing Library-description file libc-mem.mk is missing Library-description file stdcxx.mk is missing Library-description file pthread.mk is missing Library-description file libc_terminal.mk is missing Library-description file libc_pipe.mk is missing Library-description file libiconv.mk is missing Library-description file qemu-usb.mk is missing
The missing libraries are suspicious and because virtualbox depends on libc etc. it will not be built due to unresolved dependencies. I suggest you edit etc/build.conf and (as a shortcut) enable all stated repositories. Also, please be aware that Qemu is really slow when emulating hardware-virtualization features.
Regards