ppa ethereum error while installing ethereum on ubuntu

Question

i have installed ethereum on ubuntu before using the following code:

sudo apt-get install software-properties-common

sudo add-apt-repository -y ppa:ethereum/ethereum

sudo apt-get update

sudo apt-get install ethereum

now i have set a proxy and want to install ethereum.. When i run the same commands, i get the following error:

We are behind proxy. The proxy is already set.

Earlier we ran below commands and installed ethereum successfully.

sudo apt-get install software-properties-common

sudo add-apt-repository -y ppa:ethereum/ethereum

sudo apt-get update

sudo apt-get install ethereum

But now when we are trying to install ethereum in new machine of same configuration it is throwing us following error :
Cannot add PPA: 'ppa:ethereum'

I dont know if its because of the proxy.. how can i solve this?

Answer 1

First try: sudo apt-get install --reinstall ca-certificates
If it still doesn't work, then try: sudo -E add-apt-repository ppa:ethereum/ethereum

Also, you can go through this to know more: https://askubuntu.com/questions/429803/cannot-add-ppa-please-check-that-the-ppa-name-or-format-is-correct