Hmm that is an ugly consequence of being unable to make tmp writable - I think we need to find a different solution though; a competent user who is not familiar with CakePHP isn't going to expect it (or at least, I wouldn't) to make anything world writable upon install. We can/should come back to this, perhaps switching tmp to use a folder under `sys_get_temp_dir` if the app tmp dir is unwritable.