const control_mode_statusPtr& msg = event.getMessage(); // this is line 172

You're assigning to a pointer from a const pointer, which is not allowed. If you want a mutable copy you can subscribe with MessageEvent<control_mode_status> instead of MessageEvent<control_mode_status const>. You can also make a copy manually.

void controlModesStatusCallback(control_mode_status msg)
{

string publisher_name = (*(msg.__connection_header))["callerid"];
ROS_INFO_STREAM("Got control mode status, from: " << publisher_name);
latest_mode_status[node_mode_map[publisher_name]] = msg;
}

.. is there any issue with using this?

__connection_header has been deprecated for a while, and will cease to exist in a future version of roscpp.

Josh