Ruby RVM apt-get update error

Question

I get following error when trying to install anything with RVM:

Searching for binary rubies, this might take some time.
Found remote file https://rvm.io/bina         


        

Answer 1

1) Before installing ruby must be done update:

apt is preferred over apt-get for interactive use in recent Ubuntu versions and apt should fix by:

sudo apt update
sudo apt upgrade

Or with apt-get may be used --allow-releaseinfo-change

sudo apt-get --allow-releaseinfo-change update

2) After successfully installation, for example ruby-2.3.1:

rvm install 2.3.1