How to debug https without root on Android

One viable option -- use app called “Packet Capture”. This is vpn with embedded proxy & certificate authority, thanks to wich it’s capable to capture data in SSL.

This app saved me a lot of time, and it requres no root.
https://play.google.com/store/apps/detailsid=app.greyshirts.sslcapture&rdid=app.greyshirts.sslcapture

At the moment still has one limitation: cannot capture SLL on non-standard port. Problem already reported to the author.