By the time Szeged comes, the migrate path from Drupal 6 to Drupal 8 should be complete and even the Drupal 7 to Drupal 8 path should either be complete or very close. As I outlined in manual testing is indispensable. People interested in testing should have the following ready:

  1. A real Drupal 6 site, preferably scrubbed of sensitive information in case we need to make copies of the database.
  2. A developer enviroment complete with a debugger. I recommend PhpStorm + Xdebug, it's very easy to set up . Of course, you do not need to have an inside-out knowledge of migrate, I will guide people on where to break etc but without a debugger it can get quite hard to figure out what's broken.
  3. Knowledge of how to install Drupal 8 -- it's likely you will need to reinstall a "few" times. A helpful script can be found here .