UniqueIndex attribute on entity can cause some packaged CLI tools to error

[Firehed]

Bug Report

Q	A
BC Break	no
Version	3.0.0

Summary

If a table has a UniqueConstraint attribute where there's no name neing explicitly set (e.g. #[Mapping\UniqueConstraint(fields: ['email'])]), several included CLI tools produce an error:

TypeError: Doctrine\DBAL\Schema\Index::__construct(): Argument #1 ($name) must be of type ?string, int given, called in /app/vendor/doctrine/orm/src/Tools/SchemaTool.php on line 341 and defined in /app/vendor/doctrine/dbal/src/Schema/Index.php:42
Stack trace:
#0 /app/vendor/doctrine/orm/src/Tools/SchemaTool.php(341): Doctrine\DBAL\Schema\Index->__construct(0, Array, true, false, Array, Array)
#1 /app/vendor/doctrine/orm/src/Tools/SchemaTool.php(896): Doctrine\ORM\Tools\SchemaTool->getSchemaFromMetadata(Array)
#2 /app/vendor/doctrine/orm/src/Tools/Console/Command/SchemaTool/UpdateCommand.php(78): Doctrine\ORM\Tools\SchemaTool->getUpdateSchemaSql(Array)
#3 /app/vendor/doctrine/orm/src/Tools/Console/Command/SchemaTool/AbstractCommand.php(37): Doctrine\ORM\Tools\Console\Command\SchemaTool\UpdateCommand->executeSchemaCommand(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput), Object(Doctrine\ORM\Tools\SchemaTool), Array, Object(Symfony\Component\Console\Style\SymfonyStyle))
#4 /app/vendor/symfony/console/Command/Command.php(279): Doctrine\ORM\Tools\Console\Command\SchemaTool\AbstractCommand->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#5 /app/vendor/symfony/console/Application.php(1031): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#6 /app/vendor/symfony/console/Application.php(318): Symfony\Component\Console\Application->doRunCommand(Object(Doctrine\ORM\Tools\Console\Command\SchemaTool\UpdateCommand), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#7 /app/vendor/symfony/console/Application.php(169): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#8 /app/vendor/doctrine/orm/src/Tools/Console/ConsoleRunner.php(30): Symfony\Component\Console\Application->run()
#9 /app/cli(24): Doctrine\ORM\Tools\Console\ConsoleRunner::run(Object(Doctrine\ORM\Tools\Console\EntityManagerProvider\SingleManagerProvider), Array)
#10 {main}

I also tested by replacing the UniqueConstraint with an Index and that has the correct behavior. It appears isolated to unique indexes.

Current behavior

Instead of a deterministic index name being generated from the referenced values, the above error is produced.

How to reproduce

1. Define an entity with a UniqueConstraint attribute. Both fields and columns definitions reproduce this. Do not explicitly set a name.
2. Configure Doctrine otherwise per normal.
3. Run one of the following packaged CLI commands:

• orm:info
• orm:validate
• orm:schema-tool:update --dump-sql

Expected behavior

If name is specified in the attribute, it's used (this IS the current behavior). If not, one is generated based on the columns as occurred in ORM 2.x.

[BenMorel]

We have the same issue, and indeed, adding a name to each UniqueConstraint fixes it.
We're using version 3.0.1.