utf8mb4 character set causes migrations table creation to fail

[jaikdean]

I have a project using MySQL 5.6 set up to use utf8mb4 character set and utf8mb4_unicode_ci collation. Having this set means the migration_versions table fails to be created with the following error:

1071 Specified key was too long; max key length is 767 bytes

The version field length of 255 is hardcoded in Doctrine\DBAL\Migrations\Configuration\Configuration::createMigrationTable(), as is creation of the table itself, so there is no way to override the character set or adjust the field length without overriding this method.

[mikeSimonson]

That's one of the reason why utf8mb4_general_ci is recommended over utf8mb4_unicode_ci.
Nonetheless if you feel like it, I would welcome a PR to configure that.
You would need to enforce that new limitation in the MigrationFinder too thought.

[lcobucci]

Related to #538

[jwage]

Closing this as you can now set the column length.