Snapping a python3.6 app

I’m trying to build a python app which uses python3.6.
The problem is that python plugin uses python3.5 from xenial repository and in xenial the only way to install python3.6 is using a ppa.
I first tried to build the snap from ubuntu 17.10 which has got python3.6 as a default . On Artful the snap builds with python 3.6 but a run time there’s a problem with libc, since snapcraft use libc6 of ubuntu 16.04 and on my system I have an updated version of libc.
Do I need to create a custom plugin to do it?
Thanks in advance