Update Status mailer policy broken by core hooks modernization

This issue is quite severe depending upon configuration. If a production site uses the update manager to send emails, then cron will crash, resulting in a total loss of cron activity (and the pollution of the error logs with many php errors). In my site, this means that none of the automatic processing the site requires happens, resulting in a near-complete loss of functionality.

There priority guidelines for critical require that there be no workaround, so raising to major.

@danchadwick, I was able to mitigate this problem by disabling the update status override at admin/config/system/mailer/override which reverts update emails to Drupal Core's original unformatted state and allows cron to run without errors.

Micah

@micahw156 - Yes, I saw that in the issue and did mitigate it as such. Without such a mitigation, it would definitely warrant critical priority. Thank you for your report.

The problem is that Core doesn't provide an API for the information that we need. So I had to call an internal function, which has now been removed. We can check the issue that removed it to see if it explains the replacement to use.

It looks like we could do something like this

if (function_exists('update_requirements')) {
  $requirements = update_requirements('runtime');
}
else {
  $requirements = \Drupal::moduleHandler()->invoke('update', 'runtime_requirements');
}

My sites are still on D10 so I can't test it.

Here's the patch.

And here is the patch for 1.x