Problem/Motivation
In #3087644: Remove Drupal 8 updates up to and including 88**, we noticed that using that hook_update_last_removed() is not actually that strictly enforced (it requires to have an update function), doesn't actually show what's going on and just displays a warning message, together with a success message:
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Proposed resolution
Add something to system_requirements() that checks for that explicitly, for all modules implementing such a hook. Display an error with clear info and don't allow users to continue in that case.
Remaining tasks
User interface changes
(copied from #40)
Before:
you only get a warning that doesn't prevent you from doing the update and that warning only shows up on a later step when the updates are listed:
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Clik here to view.
After:
Update.php stops on the requirements page and displays an error that doesn't allow you to continue:
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Clik here to view.
Contrib:
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