Web Profiler inconsistent error - Undefined array key 4

[radar3301]

Symfony version(s) affected

6.3.1

Description

Very occassionally, when navigating '/logout' (302 redirect) '/' (302 redirect) '/login, I get the following errors:

ErrorException:
Warning: Undefined array key 4

  at symfony\http-kernel\Profiler\FileProfilerStorage.php:312
  at Symfony\Component\HttpKernel\Profiler\FileProfilerStorage->removeExpiredProfiles()
  at Symfony\Component\HttpKernel\Profiler\FileProfilerStorage->write()
  at Symfony\Component\HttpKernel\Profiler\Profiler->saveProfile()
  at Symfony\Component\HttpKernel\EventListener\ProfilerListener->onKernelTerminate()
``` and ```
BadMethodCallException:
Symfony\Component\VarDumper\Cloner\Data objects are immutable.

in symfony\var-dumper\Cloner\Data.php (line 152)
Data->offsetSet() in symfony\http-kernel\DataCollector\EventDataCollector.php (line 92)
EventDataCollector->setCalledListeners() in symfony\http-kernel\DataCollector\EventDataCollector.php (line 74)
EventDataCollector->lateCollect() in symfony\http-kernel\Profiler\Profiler.php (line 100)
Profiler->saveProfile() in symfony\http-kernel\EventListener\ProfilerListener.php (line 135)
ProfilerListener->onKernelTerminate() in symfony\event-dispatcher\Debug\WrappedListener.php (line 116)
WrappedListener->__invoke() in symfony\event-dispatcher\EventDispatcher.php (line 220)

The interesting thing (maybe?) is that '/login' returns HTTP 200, but it looks like the AJAX request is failing? But I don't have any entries in the developer console for any ajax requests... And yet the page output looks like this:

How to reproduce

No idea how to reproduce, as it's inconsistent. I'm assuming it's a delay with the file system, maybe? I don't know.

Possible Solution

No response

Additional Context

No response

[radar3301]

heh... I found these gems in the 'index.csv' file:

L364: 062a6b,404
L726: 02
L728: (empty line)

[MatTheCat]

Seems to be the same issue than in #50816 and #50913.

If you, @benjaminfunk or @Pelagoss ever manage to share a reproducer, feel free to do so!

[radar3301]

Is it even possible to mock concurrent file writes to the same file from two different requests?

[radar3301]

Closing in favor of #50947.