Build issue with Eigen::internal::traits<double> about ouster-ros

[Samahu]

Can I ask if you are building the ouster-ros driver in a standalone project or did you encounter this error when integrating the driver into a larger project? I ask this because the larger projects could affect the selected Eigen package (maybe you utilize vcpkg along with ROS).

Also mind checking the version of Eigen library that is actually in use when compiling the project by embedding the following snippet somewhere in the driver code:

#pragma message("eigen world: " BOOST_PP_STRINGIZE(EIGEN_WORLD_VERSION))
#pragma message("eigen major: " BOOST_PP_STRINGIZE(EIGEN_MAJOR_VERSION))
#pragma message("eigen minor: " BOOST_PP_STRINGIZE(EIGEN_MINOR_VERSION))

Please try that and let me know what you get.

[Samahu]

Googling around I found other instances similar to the issue you are dealing with, check this: cdcseacave/openMVS#164

I couldn't generate the problem on my machine even after switch my compiler to gcc-9.4.0. Is upgrading to a newer version of gcc an option to you?

Alternatively, you can leave the line commented out on your machine but since none of our users has reported this problem .. I am not leaning into removing the function definition.

[santumuchetty]

src/ouster-ros/src/os_ros.cpp:26:72: note: #pragma message: eigen world: 3
   26 | #pragma message("eigen world: " BOOST_PP_STRINGIZE(EIGEN_WORLD_VERSION))
      |                                                                        ^
src/ouster-ros/src/os_ros.cpp:27:72: note: #pragma message: eigen major: 3
   27 | #pragma message("eigen major: " BOOST_PP_STRINGIZE(EIGEN_MAJOR_VERSION))
      |                                                                        ^
src/ouster-ros/src/os_ros.cpp:28:72: note: #pragma message: eigen minor: 7
   28 | #pragma message("eigen minor: " BOOST_PP_STRINGIZE(EIGEN_MINOR_VERSION))
      |                                                                        ^

Here's the output of the Eigen version.
I have just cloned the repo and followed the steps to build it.

[Samahu]

I have the same version as you and I am using Ubuntu 20.04 but I was using gcc-11, after downgrading to gcc-9.4.0 which exactly what you have I still can't produce the issue. So I don't think there is something particularity bad about our code. But I would be interested to know what's causing it to fail on your machine.

[Samahu]

Not sure how to deal with this issue since it seems that it only affects your installation I will close it as is. If this affects more people only then I would consider commenting out the traists<double> line.