Install the dependencies:
sudo apt install libbenchmark1.8.3 libdisplay-info2 libevdev-dev libgav1-1 libgudev-1.0-dev libmtdev-dev libseat1 libstb0 libwacom-dev libxcb-ewmh2 libxcb-shape0-dev libxcb-xfixes0-dev libxmu-headers libyuv0 libx11-xcb-dev libxres-dev libxmu-dev libseat-dev libinput-dev libxcb-composite0-dev libxcb-ewmh-dev libxcb-icccm4-dev libxcb-res0-dev libcap-dev wayland-protocols libvulkan-dev libwayland-dev libx11-dev cmake pkg-config meson libxdamage-dev libxcomposite-dev libxcursor-dev libxxf86vm-dev libxtst-dev libxkbcommon-dev libdrm-dev libpixman-1-dev libdecor-0-dev glslang-tools libbenchmark-dev libsdl2-dev libglm-dev libeis-dev libavif-dev libluajit-5.1-dev
Download the Gamescope repository and all its submodules:
git clone https://github.com/ValveSoftware/gamescope.git --recursive
Enter the newly created 'gamescope' directory:
cd gamescope
Generate the files necessary for the Ninja build system:
meson build/
Using Ninja to compile Gamescope:
ninja -C build/
Installing Gamescope to the system:
meson install -C build/ --skip-subprojects