segfault on using mesh as collision bodies

[rohanpsingh]

Thank you for providing this impressive work.

I face a segmentation fault after a few iterations of training if I use mesh collision bodies instead of geometry primitives.
The error persists even if meshes are downsampled to have only a few faces and vertices.

To reproduce:
I use the provided ANYmal example for reproducing the error. Replace the collision tag of feet of the ANYmal example with the provided mesh. And run the anymal_blind_locomotion.py script.
That is, for all 4 feet replace this:

    <!-- Foot link -->
    <link name="LF_FOOT">
        <collision>
            <origin xyz="0 0 0.02325"/>
            <geometry>
                <sphere radius="0.035"/>
            </geometry>
        </collision>
    </link>

with this

    <!-- Foot link -->
    <link name="LF_FOOT">
        <collision>
            <origin xyz="0 0 0.02325"/>
            <geometry>
                <mesh filename="../meshes/lfoot.obj"/>
            </geometry>
        </collision>
    </link>

Downsampled meshes for left and right feet, and URDF are provided here.