This seems to be the commit that introduce the bug.

symfony/http-kernel@7b2421a

But on the logic of the Stopwatch::stopSection is not good it's just pop the last active section assuming that the id match. There is no check that the start end stop are done in the proper order.

    public function stopSection(string $id)
    {
        $this->stop('__section__');

        if (1 == \count($this->activeSections)) {
            throw new \LogicException('There is no started section to stop.');
        }

        $this->sections[$id] = array_pop($this->activeSections)->setId($id);
        $this->stop('__section__.child');
    }

Hey, thanks for your report!
There has not been a lot of activity here for a while. Is this bug still relevant? Have you managed to find a workaround?

Could I get a reply or should I close this?

If not using the profiler is a workaround, then yes.

Otherwise it is still broken.

@uncaught may I ask what is your workaround ? I have the same issue.

I think I simply used microtime() to measure the time manually back then. Sorry, not really a workaround.

Can you create a small example application that allows to reproduce your issue?

Can you create a small example application that allows to reproduce your issue?

@xabbuh, that has been fixed in #39598.
Another ticket I created is #36762 with a link to virtually the same code fix. Tested locally and seems to be working since Symfony 5.1.

@jlekowski This is not related to the messenger but the http kernel.

I have gave the exact line of the class where the issue is and also pin point the commit where the issue was introduced. Hard to be more clear than that. #36623 (comment)

True @mpoiriert, that fix did not target the root cause.

Well, without a reproducer that allows us to debug the issue in more detail I am afraid it's hard to help.

@xabbuh, a command like this is probably the simplest way to reproduce it (just run bin/console test).

<?php

namespace App\Command;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\KernelInterface;
use Symfony\Component\Stopwatch\Stopwatch;

class TestCommand extends Command
{
    /**
     * @var KernelInterface
     */
    private $kernel;

    /**
     * @var Stopwatch
     */
    private $stopwatch;

    /**
     * @param KernelInterface $kernel
     */
    public function __construct(KernelInterface $kernel, Stopwatch $stopwatch)
    {
        $this->kernel = $kernel;
        $this->stopwatch = $stopwatch;
        parent::__construct('test');
    }

    /**
     * @param InputInterface $input
     * @param OutputInterface $output
     * @return int
     */
    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $this->stopwatch->start('foo');
        $this->kernel->handle(new Request(), HttpKernelInterface::SUB_REQUEST);
        $this->stopwatch->stop('foo');
        return 0;
    }
}

see #42331 for an attempt to fix this, please give it a try and provide some feedback if that PR fixes your issue

@xabbuh, I tested your fix on my example code and it worked - the section stays open after running a sub-request.