PHP message: Xdebug: [Step Debug] Could not connect to debugging client.

[vhb-Mark]

Hi all,

I followed the steps on the xdebug.md but as soon as I start the project with Xdebug my log is spammed with the following:
NOTICE: PHP message: Xdebug: [Step Debug] Could not connect to debugging client. Tried: 172.21.0.1:9003 (through xdebug.client_host/xdebug.client_port, from xdebug://gateway)

Did I forgot something?

With kind regards

[bkosun]

Hello!

It looks like you have one of the unsuccessful use cases:
xdebug/xdebug#833 (comment)

This error appeared after the PR #461 merge. As you can see from the draft, xdebug://gateway is still not well tested:
https://docs.google.com/document/d/1W-NzNtExf5C4eOu3rRQm1WlWnbW44u3ANDDA49d3FD4

To fix this bug, use xdebug.client_host = host.docker.internal instead of xdebug.client_host = xdebug://gateway

https://docs.docker.com/desktop/networking/#i-want-to-connect-from-a-container-to-a-service-on-the-host

As far as I understand, the previous configuration method worked regardless of the platform:

symfony-docker/frankenphp/conf.d/app.dev.ini

Lines 1 to 2 in d620a51

	; See https://docs.docker.com/desktop/networking/#i-want-to-connect-from-a-container-to-a-service-on-the-host
	; See https://github.com/docker/for-linux/issues/264

symfony-docker/docker-compose.override.yml

Line 22 in d620a51

- host.docker.internal:host-gateway

Official guide to setting up Xdebug 3 + Docker + PHPStorm from the author of Xdebug:
https://www.youtube.com/watch?v=4opFac50Vwo