Until now, there are still no official support to Beta2Beta upgrade.
The latest Drupal beta release is now beta 11.
For those in a wild who are running on Drupal8 beta version, here is a little instruction to help you upgrade between each beta version.
Please understand that I can't guarantee that you will be able to do this successfully or you may even lose your site! What I am telling you is something I have discovered myself, and it works for me.
Most important: Make a back up of your Drupal database and source first!
- Install "git" on the server. In my case, I use "yum install git"
- Follow instruction on this page. Basically, you will need to clone the Head2Head module for the first time. And regularly you will need to upgrade it each time you want to upgrade between each beta.
- Login into your Drupal Site and enable Head2Head module and Beta2Beta module
- Go to /admin/config/development/beta2beta
- Select the current beta version of your installation from the drop down. I think the instruction tells you to do it only once.
- Then overwrite the source of your Drupal with the latest beta version.
- Use Drupal Console or Drush to clear the cache, and here we are. the latest beta version.
In my case, I used "drupal cache:rebuild" and got the error for the first time, but the error disappeared when I tried to clear cache again
- And here we are, the latest Drupal beta version
Next time, before upgrading the Drupal Core source
- Go to modules/head2head directory and run git pull origin 8.x-1.x
- Overwrite the previous installation of Drupal8 beta with the new one
- Then use Drupal Console or Drush to clear your cache, you may get the error like above, clear cache again and you are done!