I've been trying to do a migration from Odoo 9 to Odoo 10 using OpenUpgrade and following the documentation here; https://oca\.github\.io/OpenUpgrade/intro\.html

Unfortunately,\ the\ documentation\ is\ written\ with\ so\ much\ assumed\ knowledge\ as\ to\ be\ of\ little\ use,\ and\ some\ things\ just\ don't\ work\.\ For\ example,\ it's\ not\ possible\ to\ install\ openupgradelib\ when\ you're\ still\ on\ Python\ 2\.7\.\ This\ is\ reported\ here; https://github.com/OCA/openupgradelib/issues/159.

I've tried the official Odoo docker image for Odoo 9 along with various unofficial ones. Nothing works. I am assuming that the codebase required for running the migration is the version we're starting from, rather than the target, though this is only stated in a couple of blogs I've found, and not mentioned in the OpenUpgrade documenation.

I've found numerous blog articles that claim to show how to perform a migration, but that have such obvious errors that clearly they have not executed a migration at all. Some have even stated that you can migrate across multiple major versions in a single migration; contrary to the official documentation.

Clearly there's a lot of bad information out there. Does anyone have a single guide to migration that actually works?