Testing on windows XP, version 2.1.6.

When running "php app\console server:run" it gives:

[ErrorException]
Warning: proc_open(): CreateProcess failed, error code - 267 in D:\Source\php\site1\vendor\symfony\symfony\src\Symfony\Component\Process\Process.php line 244

Changing the value of $this->cwd to an absolute path seems to fix the problem. (see http://php.net/proc_open cwd parameter)

The class ServerRunCommand sets "docroot" parameter default value as "web/", maybe it should be null (so it gets the current dir).