ubuntu 22.04安装Eigen

1 安装

git clone https://gitlab.com/libeigen/eigen.git

cd eigen
mkdir build 
cd build
cmake ..

sudo make install

...
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/util
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/util/TemplateGroupTheory.h
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/InternalHeaderCheck.h
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/DynamicSymmetry.h
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/Symmetry.h
-- Installing: /usr/local/include/eigen3/unsupported/Eigen/CXX11/src/TensorSymmetry/StaticSymmetry.h

2 colcon build编译时报错

fatal error: Eigen/Geometry: No such file or directory

解决：创建软链接（参考：fatal error: Eigen/Geometry: No such file or directory）

sudo ln -sf /usr/include/eigen3/Eigen /usr/include/Eigen
sudo ln -sf /usr/include/eigen3/unsupported /usr/include/unsupported

另外，根据官方仓库 eigen3_cmake_module的提示对CMakeLists.txt作相应修改：
如，

find_package(eigen3_cmake_module REQUIRED)
find_package(Eigen3)

详见该链接。