Rapyuta fork of ros1_bridge breaks in 18.04

[ngiftsun]

System: Ubuntu 18.04
ros1: melodic
ros2: dashing

Traceback (most recent call last):
  File "bin/ros1_bridge_generate_factories", line 11, in <module>
    from ros1_bridge import generate_cpp
  File "/home/ros2/ros2_ws/src/ros1_bridge/ros1_bridge/__init__.py", line 709, in <module>
    rosidl_parser.Field.__hash__ = FieldHash
AttributeError: module 'rosidl_parser' has no attribute 'Field'
make[2]: *** [generated/get_factory.cpp] Error 1
make[1]: *** [CMakeFiles/ros1_bridge.dir/all] Error 2
make: *** [all] Error 2
---
Failed   <<< ros1_bridge	[ Exited with code 2 ]