Comment 2 for bug 398367

We tracked down the cause of this issue to a sanity check raising an exception in one of the installer hooks, let me explain.

The installer hook 40regen-joomla-secrets job is to regenerate a random Joomla secret key as well as set a random password for the Joomla MySQL account.

Joomla's configuration files were updated with the new password, and the call was made to the di-live component 72mysql-conf to update the database accordingly. An exception was raised and the password was never set, so Joomla could not connect to MySQL post installation:

Database error: Unable to connect to the database

Q: But then why was the MySQL root password set correctly?
A: Because the live-installer hooks and di-live components are run in different contexts (ie. one in the chroot, other not).

Q: But its always been like this, why was an exception raised now?
A: 70mysql-conf has been thoroughly updated for our upcoming release to support new and exciting use-cases (more to come on this). One of which requires that there is only one unique instance of MySQL started when not running within a chroot. One of the sanity checks raised an exception when it received an unexpected exitcode due to the pre-initialization state of MySQL in the new installation.

The fix was simple, but the consequences were severe. This issue should never had made its way into a release, and for that we apologize. We have updated our testing protocol to make sure history doesn't repeat itself.

I am currently uploading a new version to be released.