For whatever reason, nobody seems to use it. It must be a good reason or else they would. [PS: It's because it doesn't add the signing keys and maybe also because it's too associated with Ubuntu.] This, for example, is the official way to add Mozilla's repo:
echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.asc] https://packages.mozilla.org/apt mozilla main" | sudo tee -a /etc/apt/sources.list.d/mozilla.list > /dev/null
And here's Signal's instructions:
# 1. Install our official public software signing key:
wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg; cat signal-desktop-keyring.gpg | sudo tee /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null
# 2. Add our repository to your list of repositories:
wget -O signal-desktop.sources https://updates.signal.org/static/desktop/apt/signal-desktop.sources; cat signal-desktop.sources | sudo tee /etc/apt/sources.list.d/signal-desktop.sources > /dev/null
# 3. Update your package database and install Signal:
sudo apt update && sudo apt install signal-desktop
alt Hacker News
For whatever reason, nobody seems to use it. It must be a good reason or else they would. [PS: It's because it doesn't add the signing keys and maybe also because it's too associated with Ubuntu.] This, for example, is the official way to add Mozilla's repo:
And here's Signal's instructions: Bonkers.