Forge does complain about a not writeable directory if i do $form...->directory('does/not/exist').. (must contain a / )
Maybe should be changed to:
public function directory($dir = NULL)
{
// Use the global upload directory by default
empty($dir) and $dir = Config::item('upload.upload_directory');
$realpath = realpath($dir);
// Does the path exist?
if($realpath === FALSE)
throw new Kohana_Exception('upload.no_filepath', $dir);
// Make the path asbolute and normalize it
$dir = str_replace('\\', '/', $realpath).'/';
// Make sure the upload director is valid and writable
if ($dir === '/' OR ! is_dir($dir) OR ! is_writable($dir))
throw new Kohana_Exception('upload.not_writable', $dir);
$this->directory = $dir;
}