TYPO3.Flow

For reference, this is what we use, the trick is the umask in combination with our recommended permissions (sticky group bit):

if (!is_dir($path) && strlen($path) > 0) {
            $oldMask = umask(000);
            mkdir($path, 0777, TRUE);
            umask($oldMask);
            if (!is_dir($path)) throw new \F3\FLOW3\Utility\Exception('Could not create directory "' . $path . '"!', 1170251400);
        }

No, it's a more general problem. All files, also the cache files FLOW3 creates, are not writeable by the group, thus the problem exists for those as well.

Patch set 1 of change Icec4e1a7ecebf96cf07a9be09f3c9510b0679f63 has been pushed to the review server.
It is available at http://review.typo3.org/1580

Karsten Dambekalns wrote:

All files, also the cache files FLOW3 creates, are not writeable by the group, thus the problem exists for those as well.

Turns out that this is true, but still the cache files can be replaced, because we use rename to move a temporary file in place of the old file. The DOctrine ProxyFactory does not do this.