ARCO Debian package repository

Configure repository by hand.

$ sudo wget -P /etc/apt/trusted.gpg.d https://uclm-arco.github.io/debian/uclm-arco.asc

Alternatives:

$ gpg --keyserver hkps://keys.openpgp.org --recv-key 75CBD98B61DD4E1C; gpg --export 75CBD98B61DD4E1C | sudo cat > /etc/apt/trusted.gpg.d/uclm-arco.gpg

Deprecated methods:

$ sudo apt-key adv --keyserver hkps://keys.openpgp.org --recv-keys 75CBD98B61DD4E1C
$ sudo apt-key adv --fetch-keys https://uclm-arco.github.io/debian/uclm-arco.asc

And finally add the repository:

$ echo "deb [signed-by=/etc/apt/trusted.gpg.d/uclm-arco.asc] https://uclm-arco.github.io/debian/ sid main" | sudo tee /etc/apt/sources.list.d/arco.list
$ sudo apt update