I don't know why it's doing that, but I can't install the beta version:
curl https://rclone.org/install.sh | sudo bash -s beta
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 4497 100 4497 0 0 10083 0 --:--:-- --:--:-- --:--:-- 10082
curl: (18) transfer closed with 35 bytes remaining to read