When using cache:clear (in a windows-environment with administrator-rights) breaks when the $oldCacheDir is already a directory.

[ErrorException]
Warning: rename(C://envname, C://envname_old): Access denied. (code: 5) in C:~\FrameworkBundle\Command\CacheClearCommand.php line 77

I'm not sure how this behaviour is on a linux-machine, but there's simply no check at all if any directory with *_old already exists.

• Should there not be a check and create a new unique $oldCacheDir if one's already available?
• Should old cache dir's be removed?