1 php protocol_error ai_generated true

GuzzleHttp\Exception\ConnectException: cURL error 1: Protocol "http2" not supported or disabled in libcurl (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) in /var/www/app/vendor/guzzlehttp/guzzle/src/Handler/CurlFactory.php:187

ID: php/guzzle-http-version-not-supported

Also available as: JSON · Markdown · 中文
85%Fix Rate
85%Confidence
1Evidence
2024-01-10First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Guzzle 7.0 active — — —
Guzzle 7.5 active — — —
PHP 8.1 active — — —
PHP 8.2 active — — —

Root Cause

The installed libcurl version does not support HTTP/2, but the Guzzle client is configured to use 'http2' as the protocol version.

generic

中文

安装的 libcurl 版本不支持 HTTP/2，但 Guzzle 客户端被配置为使用 'http2' 作为协议版本。

Official Documentation

https://docs.guzzlephp.org/en/stable/request-options.html#version

Workarounds

  1. 90% success Downgrade the Guzzle client to use HTTP/1.1 instead: `$client = new GuzzleHttp\Client(['version' => '1.1']);` 
    Downgrade the Guzzle client to use HTTP/1.1 instead: `$client = new GuzzleHttp\Client(['version' => '1.1']);`
  2. 75% success Upgrade libcurl to a version that supports HTTP/2. On Ubuntu/Debian: `sudo apt-get update && sudo apt-get install --only-upgrade libcurl4-openssl-dev` and then recompile PHP's cURL extension. Verify with `php -i | grep cURL` and check 'cURL Information' for HTTP2 support. 
    Upgrade libcurl to a version that supports HTTP/2. On Ubuntu/Debian: `sudo apt-get update && sudo apt-get install --only-upgrade libcurl4-openssl-dev` and then recompile PHP's cURL extension. Verify with `php -i | grep cURL` and check 'cURL Information' for HTTP2 support.

中文步骤

  1. Downgrade the Guzzle client to use HTTP/1.1 instead: `$client = new GuzzleHttp\Client(['version' => '1.1']);`
  2. Upgrade libcurl to a version that supports HTTP/2. On Ubuntu/Debian: `sudo apt-get update && sudo apt-get install --only-upgrade libcurl4-openssl-dev` and then recompile PHP's cURL extension. Verify with `php -i | grep cURL` and check 'cURL Information' for HTTP2 support.

Dead Ends

Common approaches that don't work:

  1. Setting CURLOPT_HTTP_VERSION to CURL_HTTP_VERSION_2_0 manually in a custom handler 95% fail

    This does not fix the underlying libcurl limitation; it just changes the constant used, but libcurl still cannot negotiate HTTP/2.

  2. Reinstalling PHP and cURL extension via apt-get without checking the libcurl version 70% fail

    The default system libcurl on older OS versions may still lack HTTP/2 support; you need to ensure the libcurl-dev package is from a version that supports HTTP/2 (e.g., >= 7.50.0).