Invalid inertia values

[EGAlberts]

In the process of migrating from Gazebo classic to Gazebo fortress, I am publishing the robot_description from tiago_description which references the gripper contained within pal_gripper. In doing so, I get three errors:

[Err] [UserCommands.cc:1138] Error Code 18: Msg: A link named arm_1_link has invalid inertia.
[Err] [UserCommands.cc:1138] Error Code 18: Msg: A link named gripper_left_finger_link has invalid inertia.
[Err] [UserCommands.cc:1138] Error Code 18: Msg: A link named gripper_right_finger_link has invalid inertia.

By zero-ing out the inertia values (see EGAlberts@e96dc1e) of these three links I am able to make Tiago spawn.

Can you please verify the inertia values are valid? Or determine if the parsing/validation by the new version of Gazebo warrants changes?

To reproduce this issue you can simply use ros2 launch tiago_description robot_state_publisher.launch.py to publish the robot_description, and this kind of snippet with gazebo fortress running to spawn based on the published robot_description:

 robot_entity = Node(
    package="ros_gz_sim",
    executable="create",
    arguments=[
        "-topic",
        "robot_description",
        "-name",
        LaunchConfiguration("robot_name"),
    ],
    output="screen",
)

[EGAlberts]

Specifically, it seems following check is failing:

https://github.com/gazebosim/gz-math/blob/5b2522aa68be38d52bcd8f84736b4a20649f845a/include/gz/math/MassMatrix3.hh#L622

[EGAlberts]

Please also see the related issue with the tiago_robot: pal-robotics/tiago_robot#30
While the cause of the error is the same the solution is not. The finger_link's mesh is not watertight, meaning it is not straightforward to derive a new inertia matrix.