/usr/include/sofa/helper/io/ is in libsofa1-dev 1.0~beta4-9.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sofa/helper/io/Image.h
/usr/include/sofa/helper/io/ImageBMP.h
/usr/include/sofa/helper/io/ImagePNG.h
/usr/include/sofa/helper/io/ImageRAW.h
/usr/include/sofa/helper/io/MassSpringLoader.h
/usr/include/sofa/helper/io/Mesh.h
/usr/include/sofa/helper/io/MeshOBJ.h
/usr/include/sofa/helper/io/MeshTopologyLoader.h
/usr/include/sofa/helper/io/MeshTrian.h
/usr/include/sofa/helper/io/SphereLoader.h
/usr/include/sofa/helper/io/TriangleLoader.h
/usr/include/sofa/helper/io/bvh/
/usr/include/sofa/helper/io/bvh/BVHChannels.h
/usr/include/sofa/helper/io/bvh/BVHJoint.h
/usr/include/sofa/helper/io/bvh/BVHLoader.h
/usr/include/sofa/helper/io/bvh/BVHMotion.h
/usr/include/sofa/helper/io/bvh/BVHOffset.h