Deprecated function: curl_multi_exec(): Passing null to parameter #2 ($still_running) of type int is deprecated

Problem/Motivation

I'm getting this warning on /admin/config page.

Deprecated function: curl_multi_exec(): Passing null to parameter #2 ($still_running) of type int is deprecated in GuzzleHttp\Handler\CurlMultiHandler->tick() (line 128 of /var/app/current/vendor/guzzlehttp/guzzle/src/Handler/CurlMultiHandler.php)
#0 /var/app/current/web/core/includes/bootstrap.inc(347): _drupal_error_handler_real()
#1 [internal function]: _drupal_error_handler()
#2 /var/app/current/vendor/guzzlehttp/guzzle/src/Handler/CurlMultiHandler.php(128): curl_multi_exec()
#3 /var/app/current/vendor/guzzlehttp/guzzle/src/Handler/CurlMultiHandler.php(145): GuzzleHttp\Handler\CurlMultiHandler->tick()
#4 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(248): GuzzleHttp\Handler\CurlMultiHandler->execute()
#5 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(224): GuzzleHttp\Promise\Promise->invokeWaitFn()
#6 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(269): GuzzleHttp\Promise\Promise->waitIfPending()
#7 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(226): GuzzleHttp\Promise\Promise->invokeWaitList()
#8 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(269): GuzzleHttp\Promise\Promise->waitIfPending()
#9 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(226): GuzzleHttp\Promise\Promise->invokeWaitList()
#10 /var/app/current/vendor/guzzlehttp/promises/src/Promise.php(62): GuzzleHttp\Promise\Promise->waitIfPending()
#11 /var/app/current/vendor/aws/aws-sdk-php/src/AwsClientTrait.php(58): GuzzleHttp\Promise\Promise->wait()
#12 /var/app/current/vendor/aws/aws-sdk-php/src/ResultPaginator.php(131): Aws\AwsClient->execute()
#13 /var/app/current/vendor/league/flysystem-aws-s3-v3/src/AwsS3Adapter.php(293): Aws\ResultPaginator->valid()
#14 /var/app/current/vendor/league/flysystem-aws-s3-v3/src/AwsS3Adapter.php(276): League\Flysystem\AwsS3v3\AwsS3Adapter->retrievePaginatedListing()
#15 /var/app/current/web/modules/contrib/flysystem_s3/src/Flysystem/S3.php(210): League\Flysystem\AwsS3v3\AwsS3Adapter->listContents()
#16 /var/app/current/web/modules/contrib/flysystem/src/FlysystemFactory.php(183): Drupal\flysystem_s3\Flysystem\S3->ensure()
#17 /var/app/current/web/modules/contrib/flysystem/flysystem.install(83): Drupal\flysystem\FlysystemFactory->ensure()
#18 /var/app/current/web/modules/contrib/flysystem/flysystem.install(21): __flysystem_call_ensure()
#19 [internal function]: flysystem_requirements()
.......

Steps to reproduce

I'm not quite sure how to reproduce this in vanilla Drupal. Haven't tried.

Proposed resolution

The fix seems to be in here https://github.com/guzzle/guzzle/pull/2991/files and it seems to have been merged so wondering if we should push them to backport this to guzzlehttp/guzzle:6.x or should this module support guzzlehttp/guzzle:7.x ?

When I created patch for my own system with the "private $active;" -> "private $active = 0;" then the issue went away.