I made a pull request into master instead of 2.3 by error.
I just corrected this mistake.

For information, the bad PR is here #11697

Can somebody help me with travis failure ? What should I do ?

@kcassam travis fails because you gave wrong number of arguments to the constructor. It only has 3 arguments, like the main PHP exception class.

Thanks @jakzal @nicolas-grekas, i reworked my changes

👍

Cool fix :)
One question though. In the code of the last commit when the make dir fails but no error can be found and there still is no directory then no exception is thrown (but it should). If this cannot happen because there always will be an error then the error doesn`t need to be checked. If we cannot rely on an error being there then an exception should be thrown without the error message.

Question : Who will do the adaptation for version >= 2.4 because IOException constructor call are not the same :

//2.3 : 
throw new IOException(sprintf('Failed to create %s', $dir));

// >= 2.4 : 
throw new IOException(sprintf('Failed to create "%s".', $dir), 0, null, $dir);

Should I do another pull request ?

I agree with @1emming #11726 (comment)

I suggest

Simpler :

if (true !== @mkdir($dir, $mode, true)) {
    if (!is_dir($dir)) {
        // The directory was not created by a concurrent process.
        throw new IOException(sprintf('Failed to create "%s"', $dir));
    }
}

Or

More developer friendly :

if (true !== @mkdir($dir, $mode, true)) {
    $error = error_get_last();
    if (!is_dir($dir)) {
        if ($error) {
            // The directory was not created by a concurrent process. Let's throw an exception with a developer friendly error message
            throw new IOException(sprintf('Failed to create "%s": %s.', $dir, $error['message']));
        }
        throw new IOException(sprintf('Failed to create "%s"', $dir));
    }
}

Which is better ?

I commited the developer friendly version

👍

Thank you @kcassam.

Happy to have contributed. One newbie question though : How this correction will go through version of Symfony >=2.4 to master ? Do I have to redo it for each version ?

@kcassam Thanks for your help. You don't need to do anything; old branches are merged into newer ones on a regular basis. So, your changes will appear in other branches in the next days.