Passing glue string after array is deprecated. Swap the parameters in colinmollenhour/credis/Client.php on line 1414

[MountainX]

Magento 2 is failing to start. The logs show this error:

Deprecated Functionality: implode(): Passing glue string after array is deprecated. Swap the parameters in vendor/colinmollenhour/credis/Client.php on line 1414

I have a standard Redis installation. There is no custom code in the site. Redis was installed in the usual way according to these Magento Dev Docs.

Here's the code referenced by the error message:

   1406     /**
   1407      * Build the Redis unified protocol command
   1408      *
   1409      * @param array $args
   1410      * @return string
   1411      */
   1412     private static function _prepare_command($args)
   1413     {
   1414         return sprintf('*%d%s%s%s', count($args), CRLF, implode(array_map(array('self', '_map'), $args), CRLF), CRLF);
   1415     }

Has anyone run into this error yet? Is there a solution (other than disabling Redis)?

Version info:

• Magento ver. 2.3.3
• redis 5.0.7
• redis-cli 5.0.7

[colinmollenhour]

This is related to running PHP 7.4. It was fixed here: https://github.com/colinmollenhour/credis/pull/131 I just tagged it as 1.11.1

Magento2 will need to pull in the latest version.

[kirkmadera]

Confirmed that this no longer occurs in Magento 2.4.0 on PHP 7.4 which was just GA released today

[moni921]

I have magento 2.4 setup and getting above issue with php 7.4. Please help

[kirkmadera]

If you upgraded from <7.4, you might try manually clearing redis.

redis-cli flushall

or

telnet localhost 6379
flushall