Troubleshooting xdebug setup on VVV with VS Code

Here’s some tips for troubleshooting xdebug on VVV while using VSCode and Felix Becker’s PHP Debug extension and BrianGilbert_‘s Xdebug Helper for Firefox add-on.

Ensure xdebug is turned on within vvv

You may check xdebug status by taking a peak at your servers http://vvv.test/phpinfo/ page. If not on, via https://github.com/Varying-Vagrant-Vagrants/VVV/wiki/Code-Debugging we can toggle it on by accessing the virtual machine via ssh, then running a command that will turn xdebug on and restart PHP:

$ cd ~/your/location/for/vvv/
$ vagrant ssh
$ /vagrant/config/homebin/xdebug_on

The xdebug_on command is supposed to work without the full path, but I haven’t much luck with that. As a second saver, I store this full path in my text expanded since every time the machine is restarted xdebug being on does not persist and it will need to be manually turned on. A bash_alias entry could be made as well.

Ensure the browser extension is turned on

Yes, simple, but often forgotten.

Ensure you’ve started debugging in VS Code

Again, yes, simple, but often forgotten.

Check the xdebug profile is correct

Via the debug sidebar (shift+cmd+d), we’ll view our xdebug configuration file. Here’s an example of a WordPress plugin delete-thumbnails and the path I used

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Listen for XDebug",
            "type": "php",
            "request": "launch",
            "port": 9000,
            "pathMappings": {
                "/srv/www/vvv-vip/public_html/wp-content/plugins/delete-thumbnails": "${workspaceFolder}"
            },
        }
    ]
}

Two important notes:

  • VVV has two initial paths to get to your sites, /srv/and /vagrant/, the latter is a symbolic link which xdebug does not understand, you must use /srv/
  • Other tutorials may say to use ${workspaceRoot}, this variable is deprecated in favor of ${workspaceFolder}

Try a breakpoint outside of your current script

We usually want our breakpoints on what we’re working on, and we’re frustrated when xdebug doesn’t pick up on the breakpoint, so we dig around our config to check what’s wrong. Let’s first make sure that our desired code is actually running and capable of breakpointing, after all, the code not running might be why we’re firing up xdebug!

Add a breakpoint at the root of your application, somewhere you know runs 100% for sure. In WordPress, this will often be in either WordPress’ /index.php file, or the primary file in your current theme or plugin. For this plugin I’m working on, I checked that the plugin is activated, and I’ve placed a breakpoints on a fake var on the main fire which I know for sure loads:

Is your VSCode the nightly build?

I’ve heard of users being unable to run xdebug while using their beta releases. Best to always use the stable releases.


Leave a Reply

%d bloggers like this: