Problem: If you have PHP 5.3.* on your server, then you have to hardcode LswMemcacheBundle version to 2.1.8, because it's last one with correct PHP requirement,
This syntax can also be found in Command\StatisticsCommand::interact
I too have this issue trying to use the bundle in a old installation (php 5.3.10)
I'd like to avoid going back to 2.1.8 if possible.
https://github.com/LeaseWeb/LswMemcacheBundle/blob/v2.1.11/Command/ClearCommand.php line 71 uses new object syntax which is available since PHP 5.4. http://php.net/manual/en/migration54.new-features.php
Problem: If you have PHP 5.3.* on your server, then you have to hardcode LswMemcacheBundle version to 2.1.8, because it's last one with correct PHP requirement,