Segmentation Fault when implementing read/write query splitting

Description

When trying to implement read/write query splitting using a custom database component like the one detailed in the docs (https://docs.craftcms.com/v3/config/app.html#cache-component), I keep hitting a seg fault on my server (Apache).

I'm running craft in a docker container in kubernetes and can provide my docker file if necessary.

Code

'components' => [
    'db' => function() {
        $config = craft\helpers\App::dbConfig();
        $config['slaveConfig'] = [
            'username' => 'root',
            'password' => getEnv('DB_PASSWORD'),
            'tablePrefix' => 'craft_',
            'attributes' => [
                PDO::ATTR_TIMEOUT => 10,
            ],
        ];

        $config['slaves'] = [
            ['dsn' => getEnv('SLAVE_DSN_1')], 
            ['dsn' => getEnv('SLAVE_DSN_2')],
        ];
        return Craft::createObject($config);
    },
],

After a little debugging it appears that the slave dsn declaration array is what's triggering the error but I'm unclear as to why a simple array declaration would be triggering the error. Any help would be appreciated, thanks!

Additional info

• Craft version: 3.4.4
• PHP version: 7.2
• Database driver & version: mysql