#657 breaks downloads towards https://api.wordpress.org/ and many other sites when using Curl 7.29.0 (and perhaps other versions)

Error: RuntimeException: Failed to get url 'https://api.wordpress.org/core/version-check/1.7/?locale=en_US': cURL error 28: Operation timed out after 10000 milliseconds with 807 out of -1 bytes received.

It also causes issues with the REST API in Site Health with the error: REST API response: (http_request_failed) cURL error 28: Operation timed out after 10005 milliseconds with XXX out of XXX bytes received”

It also prevents WordPress plugin and core updates, basically anything that relies on the internal Curl handler in WordPress.

Adding back Connection: Close solves the issue. Please revert #657 ASAP and push the fix to WordPress 6.4

If you are just looking to fix the cURL timeouts issue in WordPress 6.4 Read here:

To fix the issue, replace /wp-includes/Requests/src/Transport/Curl.php with the following file: Curl.php.zip or see #838 (comment)

UPDATE: No need to do any manual fix, updating the WordPress Core to release 6.4.1 should work just fine now and resolve the issue.