Using fixtures with LiipFunctionalTestBundle and Postgresql

I'm trying to implement functional tests with Liip's FunctionalTestBundle in a legacy Symfony 2.8 project.

This project uses hand-written postgresql queries in repositories and such, so I cannot force the usage of sqlite. Based on the bundle's documentation, I have to create the schema myself on test setup. I tried using the code snippet provided in the documentation.

public function setUp()
{
    $em = $this->getContainer()->get('doctrine')->getManager();
    if (!isset($metadatas)) {
        $metadatas = $em->getMetadataFactory()->getAllMetadata();
    }

    $schemaTool = new SchemaTool($em);
    $schemaTool->dropDatabase();

    if (!empty($metadatas)) {
        $schemaTool->createSchema($metadatas);
    }

    $this->postFixtureSetup();
}

This fails on $schemaTool->createSchema($metadatas); with the following error:

SQLSTATE[42P06]: Duplicate schema: 7 ERROR:  schema "app" already exists' while executing DDL: CREATE SCHEMA app

/path/to/project/vendor/doctrine/orm/lib/Doctrine/ORM/Tools/ToolsException.php:39
/path/to/project/vendor/doctrine/orm/lib/Doctrine/ORM/Tools/SchemaTool.php:96

My configuration is as follows:

# /path/to/project/app/config/config_test.yml
doctrine:
dbal:
    default_connection: airlinesManager
    connections:
        airlinesManager:
            driver: pdo_pgsql
            memory: true
            path:   "%kernel.cache_dir%/test.db"

Dependencies:

# /path/to/project/composer.json
{
    [...]
    "require": {
        "php": "^7.1",
        "symfony/symfony": "2.8.*",
        "doctrine/orm": "^2.4.8",
        "doctrine/doctrine-bundle": "~1.4",
        "doctrine/common": "2.*",
        "doctrine/dbal": "2.*",
        "doctrine/doctrine-fixtures-bundle": "2.*",
        [...]
    },
    "require-dev": {
        [...],
        "liip/functional-test-bundle": "^1.10"
    },
    [...]
}

Should I change my config to driver: pdo_sqlite and remove the setUp snippet, everything works fine as long as fixtures are concerned. But I start getting errors when tests start using some hand-written postgresql queries.

Any ideas to make the schema thing work?

NB: For some reasons I cannot do any database operation from the symfony console. Here is an example when trying to drop the database.

php app/console doctrine:database:drop --force --env="test"

I always get the same error.

Could not drop database for connection named /path/to/project/app/cache/test/test.db
An exception occurred while executing 'DROP DATABASE /path/to/project/app/cache/test/test.db':

SQLSTATE[42601]: Syntax error: 7 ERROR:  syntax error at or near "/"
LINE 1: DROP DATABASE /path/to/project/...

Then again, this works fine when using sqlite.