Your composer.json requires phpredis 2.2.5, but your code requires >= 2.6.12

[mbroadhead]

Hi,
Your composer.json only requires phpredis 2.2.5:
https://github.com/ronnylt/redlock-php/blob/master/composer.json#L12

Your actual code requires phpredis >= 2.6.12:
https://github.com/ronnylt/redlock-php/blob/master/src/RedLock.php#L99

For details, see this:
phpredis/phpredis@711f053

When I run your test with phpredis 2.2.5, I get a Segmentation Fault.

I would recommend you update your composer.json to require phpredis >= 2.6.12

[brianV]

This looks like a misunderstanding.

The extended set commands are supported in Redis >= 2.6.12. Note that this is not the PHP library, but the actual Redis server.

phpredis has supported the extended commands since version 2.2.4.