How to use two default versions of Python in FreeBSD?

Question

FreeBSD

Good afternoon, I want to build gnome3 from ports, the default system is Python 2.7 and the port is built until it hits a dependency that requires Python version 3.4 or higher and the build stops with an error. DEFAULT_VERSIONS in /etc/make.conf tried - does not help.

Answer 1

on an empty stomach - only one pie
but nobody canceled virtualenv