Curl is not working if extension enabled

I wanted to try this database but it is difficult to integrate with php. Firstly php-fpm speed is very slow. Some complex query with avg 100 requests per seconds. But nginx + php7.1-fpm 15-20 rps on my macbook air.

I canceled the project because of this speed. But I noticed that the curl library did not work on my other project. I disabled couchbase extension and everything works. How can this be? What does this library affect?

PHP Version 7.1.3
Curl: 7.43.0
Couchbase SDK: 2.3.2 (installed with brew install php71-couchbase)
Couchbase Server: 5.0 Beta

And why php-fpm is very slow.

Could you set couchbase.log_level to TRACE and post your logs while you measure the speed under fpm. Also the test script.

Regarding curl, could you make sure that php_curl is loaded before php_couchbase?