Warning: Undefined array key "function" in Drupal\Core\Utility\Error::getLastCaller() (line 130 of core/lib/Drupal/Core/Utility/Error.php).

Interesting! Is there a reliable list of steps to reproduce this?

How we have handled other tickets like this is to investigate why the array key wasn't set when it was expected. Adding an isset or empty check may just be masking a larger issue.

True, but this is in a backtrace, derived from $exception->getTrace(), so it's something on the PHP side I think, not something that any Drupal code could be doing "wrong". Possibly we shouldn't even call getLastCaller if there isn't one.

Yesterday, I got the same error when playing around with drush generate and routes. Unfortunately, I have tried yesterday and today and I am not able to reproduce it. It is rather frustrating.

$ddev drush generate yml:routing generates this, test.routing.yml.

test.example:
  path: '/test/example'
  defaults:
    _controller: '\Drupal\test\Controller\TestController::build'
    _title: 'Example'
  requirements:
    _permission: 'some permission'

In the TestController return the wrong object

  public function  build() {
    return parent::formBuilder();
  }

The results is WSOD

The website encountered an unexpected error. Try again later.

Symfony\Component\HttpKernel\Exception\ControllerDoesNotReturnResponseException: The controller must return a "Symfony\Component\HttpFoundation\Response" object but it returned an object of type Drupal\Core\Form\FormBuilder. in () (line 98 of core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php).

Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 59)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 711)
Drupal\Core\DrupalKernel->handle() (Line: 19)

and a warning

Warning: Undefined array key "function" in Drupal\Core\Utility\Error::getLastCaller() (line 150 of /var/www/html/core/lib/Drupal/Core/Utility/Error.php)

#0 /var/www/html/core/includes/bootstrap.inc(164): _drupal_error_handler_real()
#1 /var/www/html/core/lib/Drupal/Core/Utility/Error.php(150): _drupal_error_handler()
#2 /var/www/html/core/lib/Drupal/Core/Utility/Error.php(63): Drupal\Core\Utility\Error::getLastCaller()
#3 /var/www/html/core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php(84): Drupal\Core\Utility\Error::decodeException()
#4 [internal function]: Drupal\Core\EventSubscriber\FinalExceptionSubscriber->onException()
#5 /var/www/html/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func()
#6 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(239): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch()
#7 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(91): Symfony\Component\HttpKernel\HttpKernel->handleThrowable()
#8 /var/www/html/core/lib/Drupal/Core/StackMiddleware/Session.php(59): Symfony\Component\HttpKernel\HttpKernel->handle()
#9 /var/www/html/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle()
#10 /var/www/html/core/lib/Drupal/Core/StackMiddleware/ContentLength.php(28): Drupal\Core\StackMiddleware\KernelPreHandle->handle()
#11 /var/www/html/core/modules/big_pipe/src/StackMiddleware/ContentLength.php(32): Drupal\Core\StackMiddleware\ContentLength->handle()
#12 /var/www/html/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\big_pipe\StackMiddleware\ContentLength->handle()
#13 /var/www/html/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass()
#14 /var/www/html/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle()
#15 /var/www/html/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle()
#16 /var/www/html/core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php(36): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle()
#17 /var/www/html/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\AjaxPageState->handle()
#18 /var/www/html/core/lib/Drupal/Core/DrupalKernel.php(711): Drupal\Core\StackMiddleware\StackedHttpKernel->handle()
#19 /var/www/html/index.php(19): Drupal\Core\DrupalKernel->handle()
#20 {main}

And this is the $backtrace array

(
    [0] => Array
        (
            [line] => 98
            [file] => /var/www/html/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php
        )

    [1] => Array
        (
            [line] => 181
            [file] => /var/www/html/vendor/symfony/http-kernel/HttpKernel.php
        )

    [2] => Array
        (
            [file] => /var/www/html/vendor/symfony/http-kernel/HttpKernel.php
            [line] => 76
            [function] => handleRaw
            [class] => Symfony\Component\HttpKernel\HttpKernel
            [type] => ->
        )

    [3] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/Session.php
            [line] => 59
            [function] => handle
            [class] => Symfony\Component\HttpKernel\HttpKernel
            [type] => ->
        )

    [4] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php
            [line] => 48
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\Session
            [type] => ->
        )

    [5] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/ContentLength.php
            [line] => 28
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\KernelPreHandle
            [type] => ->
        )

    [6] => Array
        (
            [file] => /var/www/html/core/modules/big_pipe/src/StackMiddleware/ContentLength.php
            [line] => 32
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\ContentLength
            [type] => ->
        )

    [7] => Array
        (
            [file] => /var/www/html/core/modules/page_cache/src/StackMiddleware/PageCache.php
            [line] => 106
            [function] => handle
            [class] => Drupal\big_pipe\StackMiddleware\ContentLength
            [type] => ->
        )

    [8] => Array
        (
            [file] => /var/www/html/core/modules/page_cache/src/StackMiddleware/PageCache.php
            [line] => 85
            [function] => pass
            [class] => Drupal\page_cache\StackMiddleware\PageCache
            [type] => ->
        )

    [9] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php
            [line] => 48
            [function] => handle
            [class] => Drupal\page_cache\StackMiddleware\PageCache
            [type] => ->
        )

    [10] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php
            [line] => 51
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\ReverseProxyMiddleware
            [type] => ->
        )

    [11] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php
            [line] => 36
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\NegotiationMiddleware
            [type] => ->
        )

    [12] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php
            [line] => 51
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\AjaxPageState
            [type] => ->
        )

    [13] => Array
        (
            [file] => /var/www/html/core/lib/Drupal/Core/DrupalKernel.php
            [line] => 711
            [function] => handle
            [class] => Drupal\Core\StackMiddleware\StackedHttpKernel
            [type] => ->
        )

    [14] => Array
        (
            [file] => /var/www/html/index.php
            [line] => 19
            [function] => handle
            [class] => Drupal\Core\DrupalKernel
            [type] => ->
        )

)

Hello everyone
I have followed all the steps mentioned in #11 and i am able to replicate this issue.
$callback[1] key is not have function key for this condition.
so this is trowing the warning , after checking isset condition for this it will skip this if condition for this so not showing the warning.
please review . thanks

Was able to reproduce the warning & the patch fixes the issue. Marking RTBC.

Needs test coverage.

But still think we need to figure out why that value is empty vs just putting a isset check

@shalini_jha, are you sure that the patch fixed the problem? The fail was in the 'else' of that 'if' block, not the 'if'.

I created a test from my results in #11 and then made the fix. The error message in #11 is the same as the in Issue summary and the failure on the same line 130 in 9.5.x and 150 in 11.x.

That look great @quietone!

Ran the test locally as I can't run the test-only feature

Undefined array key "function"
 /var/www/html/vendor/symfony/phpunit-bridge/DeprecationErrorHandler.php:132
 /var/www/html/web/core/lib/Drupal/Core/Utility/Error.php:150
 /var/www/html/web/core/tests/Drupal/Tests/Core/Utility/ErrorTest.php:27
 /var/www/html/web/vendor/phpunit/phpunit/src/Framework/TestResult.php:728
 /var/www/html/web/vendor/phpunit/phpunit/src/Framework/TestSuite.php:684
 /var/www/html/web/vendor/phpunit/phpunit/src/Framework/TestSuite.php:684
 /var/www/html/web/vendor/phpunit/phpunit/src/Framework/TestSuite.php:684
 /var/www/html/web/vendor/phpunit/phpunit/src/TextUI/TestRunner.php:651
 /var/www/html/vendor/phpunit/phpunit/src/TextUI/Command.php:144
 /var/www/html/vendor/phpunit/phpunit/src/TextUI/Command.php:97

Which shows the coverage. This change seems good to mark now.

Coincidentally I ran into this one this week, it didn't bother me enough to file an issue but then it turns up in the RTBC queue.

Made a suggestion to make the code slightly easier to read, otherwise this looks good to me.

This doesn't fully work though, I'm still seeing PHP warnings:

Warning: Undefined array key "function" in Drupal\Core\Utility\Error::decodeException() (line 70 of core/lib/Drupal/Core/Utility/Error.php).
Drupal\Core\Utility\Error::decodeException(Object) (Line: 69)
Drupal\Core\EventSubscriber\ExceptionLoggingSubscriber->onError(Object) (Line: 118)
Drupal\Core\EventSubscriber\ExceptionLoggingSubscriber->onException(Object, 'kernel.exception', Object)
call_user_func(Array, Object, 'kernel.exception', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.exception') (Line: 239)
Symfony\Component\HttpKernel\HttpKernel->handleThrowable(Object, Object, 1) (Line: 91)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 704)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

https://git.drupalcode.org/project/drupal/-/blob/a201c7006b4280be0ec65bb...

With the changes from the MR, there may be cases where the 'function' key may never be returned by Drupal\Core\Utility\Error::getLastCaller, for exemple if $backtrace[1] is set but doesn't have a 'class' or 'function' key.
Resulting in the warning above.

See an example of a dpm of the backtrace :

array:15 [▼
  0 => array:2 [▼
    "line" => 98
    "file" => "/var/www/html/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php"
  ]
  1 => array:2 [▼
    "line" => 181
    "file" => "/var/www/html/vendor/symfony/http-kernel/HttpKernel.php"
  ]
  2 => array:5 [▼
    "file" => "/var/www/html/vendor/symfony/http-kernel/HttpKernel.php"
    "line" => 76
    "function" => "handleRaw"
    "class" => "Symfony\Component\HttpKernel\HttpKernel"
    "type" => "->"
  ]
  3 => array:5 [▶]
  4 => array:5 [▶]
...
]

A fallback case could perhaps be added after the elseif, maybe something similar to the current else case?
https://git.drupalcode.org/project/drupal/-/blob/a201c7006b4280be0ec65bb...

Maybe the 'class' or 'function' keys could be pulled from $backtrace[2], if they can't be pulled from $backtrace[1]? (see backtrace above)

Not sure if that's a case that needs to be covered by the method though ...

This case corresponds to the following exception: (Controller returning NULL instead of a Response)
Symfony\Component\HttpKernel\Exception\ControllerDoesNotReturnResponseException : The controller must return a "Symfony\Component\HttpFoundation\Response" object but it returned null. Did you forget to add a return statement somewhere in your controller? in (line 98 of /web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php).

Any advice, guidance or suggestions on how to best handle this limit case, would be particularly appreciated.
Thanks in advance !

Hi, I have followed all the steps mentioned in #11 and I can replicate this issue.
so this is throwing the warning, I have added the patch
please review. thanks

Patch appears to be the same as MR.

@himanshu_jhaloya: Manually attaching patches is being phased out, and you should create a patch (or update existing) and Merge Request with the Gitlab integration.

DrupalCI and all patch testing will be turned off on July 1, 2024 →

I get the issue error so many times in my site, and I don't know why. I started to see it after update to D10.1, or D10.2. I added the patch from the MR 6299, and it not fix my errors:

Warning: Undefined array key "function" in Drupal\Core\Utility\Error::decodeException() (line 70 of core/lib/Drupal/Core/Utility/Error.php).

Drupal\Core\Utility\Error::decodeException(Object) (Line: 69)
Drupal\Core\EventSubscriber\ExceptionLoggingSubscriber->onError(Object) (Line: 118)
Drupal\Core\EventSubscriber\ExceptionLoggingSubscriber->onException(Object, 'kernel.exception', Object)
call_user_func(Array, Object, 'kernel.exception', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.exception') (Line: 239)
Symfony\Component\HttpKernel\HttpKernel->handleThrowable(Object, Object, 1) (Line: 91)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 53)
Asm89\Stack\Cors->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

We are using D10.3.2, update many times from D9.5, with Olivero subtheme, and so many custom and contrib modules.

Sorry for not get more information, I hope that this trace get the trick.