# Pastebin hVG5z4sx
$ export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/opt/pitivi/bin
$ sudo port select --set python3 python36
Selecting 'python36' for 'python3' succeeded. 'python36' is now active.
$ which python3                          
/opt/pitivi/bin/python3
$ /opt/pitivi/bin/pkg-config --list-all | grep python