crystaldust/lio_sam_ros2

# The AUR packages will compile from the source code, which takes some time.
$ yaourt --noconfirm pcl # select the aur/pcl
$ yaourt --noconfirm gtsam # select the aur/gtsam, or aur/gtsam-mkl if you install on an Intel CPU

# Install PCL
$ apt install libpcl-dev

# Install GTSAM
# Add PPA
sudo add-apt-repository ppa:borglab/gtsam-release-4.0
sudo apt update  # not necessary since Bionic
# Install:
sudo apt install libgtsam-dev libgtsam-unstable-dev
# More details:
# https://gtsam.org/get_started/

$ mkdir ~/lio-sam-ros2-deps/src -p # or anywhere you like
$ cp ./deps.repos ~/lio-sam-ros2-deps
$ cd ~/lio-sam-ros2-deps/
$ vcs import src/ < deps.repos
$ colcon install --merge-install --cmake-args "-DCMAKE_CXX_STANDARD_LIBRARIES=-lpython3.9" # You might need the cmake-args if you're using a new Python version
$ source install/setup.bash # Don't forget to source the environment!

# Make sure you are now at the root of the lio-sam-ros2 project
# The CPLUS_INCLUDE_PATH should be specified explicitly, or colcon won't find the perception related headers
# This is strange, should take a look and figure out why.
$ CPLUS_INCLUDE_PATH=~lio-sam-ros2-deps/install/include/ colcon build
$ souce install/setup.bash