The “cannot create download package” for Ukrainian users fix:
If you are installing from Ukraine, you may face the “cannot create download package” error because the first mirror which is automatically selected for you is based on yandex.ru domain (which is blocked by most of your ISP’s).
Here’s what may serve as workaround (close the installer and open a terminal):
Edit your mirrorlist:
and comment the row that contains yandex.ru domain (it should be the first one)
Then run cnchi (the installer) again with these parameters:
sudo -E cnchi -dv --disable-rank-mirrors