vscode-php-debug: XDebugError: command is not available

Hi,

I’m using this awesome extension for a while and sometimes in the Debug Console it shows the error XDebugError: command is not available. The debug still works fine after that, but the Debug Console often shows that error.

PHP version: 7.4.3 XDebug version: 2.9.6-7.4 Adapter version: v1.14.5

launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Listen for XDebug",
            "type": "php",
            "request": "launch",
            "port": 9000
        },
        {
            "name": "Launch currently open script",
            "type": "php",
            "request": "launch",
            "program": "${file}",
            "cwd": "${fileDirname}",
            "port": 9000
        }
    ]
}

XDebug php.ini config:

zend_extension = C:\xampp\php\ext\php_xdebug-2.9.6-7.4-vc15-x86_64.dll
xdebug.remote_enable = 1
xdebug.remote_autostart = 1
xdebug.remote_host = localhost
xdebug.remote_handler=dbgp
xdebug.remote_port = 9000

Error log:

connection 342: read ECONNRESET
XDebugError: command is not available
    at new Response (c:\Users\Marcelo\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:58:19)
    at Connection.<anonymous> (c:\Users\Marcelo\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:613:20)
    at Generator.next (<anonymous>)
    at fulfilled (c:\Users\Marcelo\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:5:58)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:94:5) {
  code: 5,
  name: 'XDebugError'
}
connection 363: read ECONNRESET

Code snippet to reproduce: It just randomly shows the error in any endpoint of my laravel application.

About this issue

Original URL
State: closed
Created 3 years ago
Reactions: 5
Comments: 24 (10 by maintainers)

Most upvoted comments

Hi @tvvocold . I’ll try, but might not be able to reproduce. A new release is imminent that will also have extended logging. The extension will also log all Xdebug traffic and that should then make it trivial for me to analyze such errors. Should be out in a day or so. I’ll let you know and will ask you to try to reproduce the error again with logging on.

Thanks!

zobo on Jun 1, 2021

This should be solved with the new breakpoint management subsystem. Let me know if there are more problems.

zobo on May 6, 2021

Hello @R0Wi . I have researched the issue and came to the following conclusion; It’s a design issue.

The issue happens when there are concurrent scripts being debugged. There is an already related PR #366, but I’ll need to check this specific behavior anyway.

The debug adapter (this extension) gets calls from vscode (setBreakPointsRequest, setExceptionBreakPointsRequest, setFunctionBreakPointsRequest). This happens when the user changes any breakpoint or on the start of the debugging session. So if concurrent debug sessions exist (like in your log) VSCode will call those at the beginning of every session.

In each of those calls, for each connection a list of existing breakpoints is fetched from Xdebug, then the list is updated by removing current breakpoints and adding them again.

The limitation of Xdebug is that the DBGp connection is blocking, and nothing is processed on it, as long as the php process is executing code. Only after a break is hit, there can be any communication on it.

Because I see a <response ... command="run" transaction_id="6" status="break"... just before the issue, and a bunch of duplicate breakpoint_list and breakpoint_remove my conclusion is that at least two setBreakPointsRequest calls are running in parallel, because while one connection is in running state, at least two more got initiated and each of them caused a setBreakPointsRequest from VSCode.

The proper way to solve this is to delegate the breakpoint management code down from the adapter to the connection level. And research how to properly handle multiple concurrent connections - be it “threads” or some other way.

@R0Wi next time I’ll also ask for the VSCode debug log (enabled in launch.json).

I’ll try to make a PR when time permits and have a look at it with @felixfbecker and @derickr - whenever they have time.

zobo on Feb 1, 2021

Happens here also. Sometimes I need to restart debugging session to get over it. Sometimes I restart whole Visual Studio too. Dunno what causes this.

wellu on Jan 13, 2021

Same problem here with my Zend application.

PHP version: 7.1.24 XDebug version: 2.9.8-7.1 Adapter version: v1.14.5

XDebugError: command is not available
    at new Response (c:\Users\Allan\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:58:19)
    at Connection.<anonymous> (c:\Users\Allan\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:613:20)
    at Generator.next (<anonymous>)
    at fulfilled (c:\Users\Allan\.vscode\extensions\felixfbecker.php-debug-1.14.5\out\xdebugConnection.js:5:58)
    at processTicksAndRejections (internal/process/task_queues.js:94:5) {
  code: 5,
  name: 'XDebugError'
}

allanwolski on Jan 11, 2021

Hi @L3P3. I was looking for the right solution and came up with this https://github.com/xdebug/vscode-php-debug/pull/517. It’s taking a lot longer to implement as the changes are quite dramatic.

I’ll try to provide a quick patch for the issue within the current plugin framework.

Once I have the other branch ready, would you be willing to test a prerelease?

Best!

zobo on Mar 4, 2021

So what does this mean guys? I want to debug a Magento 2 application and just use vs code for years now. There seems to be a connection since in the debug view, it lists active requests appearing and disappearing. When I set a breakpoint thou, it says “command not supported” and “no such breakpoint”. Is the bottom line for me now just “nope, cannot do it”? Or what? Thanks

L3P3 on Mar 4, 2021