distance_map | ROS package for converting OccupancyGrid | Robotics library

The problem is that your constructor for FlatlandCBS is invalid. As per cppreference:

Before the compound statement that forms the function body of the constructor begins executing, initialization of all direct bases, virtual bases, and non-static data members is finished. Member initializer list is the place where non-default initialization of these objects can be specified.

The error you get - error: no matching function for call to ‘boost::python::numpy::ndarray::ndarray()’ - is the compiler telling you it has tried to use the default constructor of ndarray. This class doesn't have a default constructor, so you need to specify a different constructor to use in the initializer list (just like you did for m_railEnv!). The simplest solution here would be to move map's initialization into the initializer list like this: