This guide walks through installing the Cosmic Desktop Environment.
⚠️ WARNING Follow these steps in order. Do not restart your computer until explicitly told to do so in Step 5.
Add Repositories & Install COSMIC
Run the following commands to add the repository, import the GPG key, update your system, and install the session manager.
# Step 1
# 1. Add the repository
echo 'deb http://download.opensuse.org/repositories/home:/nomispaz:/debian:/cosmic-desktop/Debian_13/ /' | sudo tee /etc/apt/sources.list.d/home:nomispaz:debian:cosmic-desktop.list
# 2. Add the GPG key
curl -fsSL https://download.opensuse.org/repositories/home:/nomispaz:/debian:/cosmic-desktop/Debian_13/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_nomispaz_debian_cosmic-desktop.gpg > /dev/null
# 3. Update and Install
sudo apt update
sudo apt install cosmic-session
## Step 2: Critical Warning
DO NOT CHANGE YOUR WINDOW MANAGER AND DO NOT RESTART YET.
Proceed immediately to Step 3.
## Step 3: Swap LightDM for GDM
COSMIC requires GDM (GNOME Display Manager). During the installation, you should be prompted to select your default display manager. Select gdm3.
sudo apt install gdm3
sudo dpkg-reconfigure gdm3
## Step 4: Create Configuration Files
Create the required configuration directory and generate valid (empty) configuration files using the RON format.
# Create COSMIC config directory
mkdir -p ~/.config/cosmic
# Create empty-but-valid shortcuts file
cat > ~/.config/cosmic/shortcuts.ron << 'EOF'
(
)
EOF
# Create empty-but-valid tiling exceptions file
cat > ~/.config/cosmic/tiling_exceptions.ron << 'EOF'
(
)
EOF
## Generate Remaining Files
Run the empty session manually to generate the remaining necessary files.
sudo reboot