virtualbox not available in repos –

Why is virtualbox-ose missing from the repos?
Virtualbox-ose-kmod and virtualbox-ose-additions are present, but no virtualbox-ose.
I tried in both oktopkg and in software station, both are not showing virtualbox-ose.

It is available in ports.
I tried installing /emulators/virtualbox-ose from ports, but it failed with:

===> FAILED Applying FreeBSD patch-kBuild_env.sh
===> FAILED to apply cleanly FreeBSD patch(es) patch-kBuild_env.sh
*** Error code 1

Any help will be appreciated.

I am a new user of GhostBSD, but a long time user of Linux Debian.
I have earlier installed virtualbox on GhostBSD, but after reinstalling GhostBSD, I can no longer find virtualbox-ose.

Thanks in advance,
K. Ghosh