Symfony version(s) affected

7.1

Description

When the container fails to build (e.g. due to misconfigured services), Symfony does not release the lock created here. This causes subsequent calls to bootKernel() (e.g., in a test suite running multiple tests) to freeze indefinitely on flock().

Steps to Reproduce

1. Create a misconfigured service (e.g. missing required constructor argument).
2. Create a PHPUnit test with at least 2 test cases and a setup method that boots the kernel.
3. Run tests.
4. Watch it freeze on the second test case setUp method.

Actual Behaviour
The first test's setUp method is executed and bootKernel is called, it throws as expected because of misconfigured service, but the .lock file is not released.

The second test's hangs indefinitely while trying to acquire the lock.

No cleanup happens when the exception is thrown.

Expected Behaviour
The .lock file should be released when compiling the container fails, to prevent deadlocks or the tests should fail immediately.

Relevant file
Kernel.php

How to reproduce

1. Clone the repository and install dependencies.
2. Observe the misconfigured PostRepository service (missing constructor call).
3. Run tests: bin/phpunit tests/ExampleTest.php

Temporal work around

class TestKernel extends BaseKernel
{
    /**
     * @throws Throwable
     */
    protected function initializeContainer(): void
    {
        try {
            parent::initializeContainer();
        } catch (Throwable $e) {
            $class     = $this->getContainerClass();
            $buildDir  = $this->getBuildDir();
            $cache     = new ConfigCache($buildDir . '/' . $class . '.php', $this->debug);
            $cachePath = $cache->getPath() . '.lock';

            @unlink($cachePath);

            throw $e;
        }
    }
}