<br />
<b>Warning</b>:  session_start(): open(/var/lib/php/sessions/sess_5kks3s6n7gh0kab22evfpf7rhl, O_RDWR) failed: No space left on device (28) in <b>/var/www/tb-usercake/models/config.php</b> on line <b>51</b><br />
<br />
<b>Warning</b>:  session_start(): Failed to read session data: files (path: /var/lib/php/sessions) in <b>/var/www/tb-usercake/models/config.php</b> on line <b>51</b><br />
static File installOrUpdateYouTubeDL() {
  File file = youTubeDLExecutable();
  if (!file.exists()) ret forceInstallYouTubeDL();
  pcall {
    // TODO: always -1
    long size = urlSizeByHEAD(youTubeDL_URL());
    print("youtube-dl size on server: " + size);
    if (size > 0 && size != fileSize(file))
      ret forceInstallYouTubeDL();
  }
  ret file;
}