MySQL has a check if its able to be upgrade before it does it. This is largely internal in the checks of the document/code:
A similar test for example was suggested that we need to do in MariaDB. Given the large kb pages on incompatibilities I think this is something that can at least be partially automated in a check program.
The goal is to advice users if an existing MySQL instance has any incompatibilities to note before a user tries to cross-upgrade to MariaDB.
So the goal would be to check on a database/global scale looking at tables, at features used, at settings, at character sets in table and determine the migratablilty