Edge case template render bug.

[KendallHopkins]

After staging to our production servers (after which we clear the cache), I often get this type of error: File exists in /path/../Twig/lib/Twig/Environment.php at 950. The error only happens once and I'm assuming it's an edge case where is_dir returns false on two threads at once, and then one thread fails the mkdir.

if (!is_dir(dirname($file))) {
    mkdir(dirname($file), 0777, true); // this is line 950
}

Is there a way to avoid this type of error in the give framework? Would it be possible to only allow PHP thread to render a template at the same time to prevent duplicate rendering and preventing errors like this?