Description:
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PHP 7.1 fails to connect to MySQL 8.0.x because of charset incompatibility with MySQL 8.0's new default server charset of utf8mb4.

The workaround is to change the server charset back to pre-MySQL 8.0 default of utf8.

Test script:
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$mysqli = new mysqli('127.0.0.1', 'root', 'xxxx', 'test');

$pdo = new PDO('mysql:host=127.0.0.1;dbname=test', 'root', 'xxxx');


Expected result:
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There should be no error.

Actual result:
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Error when using mysqli:

PHP Warning:  mysqli::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers in ... on line 3

Error when using PDO_MYSQL:

Connection failed: SQLSTATE[HY000] [2054] Server sent charset unknown to the client. Please, report to the developers