For recent Ubuntu releases:

1. Build

# install dependencies
sudo apt build-dep mesa
# create source directory
mkdir -p ~/src && cd ~/src
# checkout source
git clone https://gitlab.freedesktop.org/mesa/mesa.git && cd mesa
# build and deploy
mkdir build-`git describe --always --tags`
cd build-`git describe --always --tags`
meson .. --prefix=/usr/local-`git describe --always --tags`
sudo ninja install
# symlink deployment directory to /usr/local
sudo ln -sfn /usr/local-`git describe --always --tags` /usr/local

2. Configure

Add the following lines to /etc/environment:

# Override GL driver path.
# The Steam UI and some game launchers require 32-bit libraries,
# so we include the 32-bit system library path.
LIBGL_DRIVERS_PATH=/usr/local/lib/x86_64-linux-gnu/dri:/usr/lib/x86_64-linux-gnu/dri

# Override Vulkan ICD path.
# Here Intel is used; replace with other vendor ICDs as needed.
VK_ICD_FILENAMES=/usr/local/share/vulkan/icd.d/intel_icd.x86_64.json

3. Reload Environment

The Gnome Desktop Environment must be reloaded using the new environment. Rebooting works, but it’s slow. To reload faster, switch to a new virtual console and start a new session, then restart the Gnome session manager with the following command:

sudo systemctl restart gdm3

Debug

# Check that Vulkan is using correct the driver revision.
vulkaninfo --summary | grep driverInfo

# Display sorted environment variables;
# verify LIBGL_DRIVERS_PATH and VK_ICD_FILENAMES are set.
env | sort

# Check journalctl for errors.
journalctl -b | grep gdm-x-session