Message named pkg/Duration with field builtin_interfaces/Duration is invalid

Generated by Generative AI

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Operating System:

Linux

ROS version or commit hash:

rolling

RMW implementation (if applicable):

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RMW Configuration (if applicable):

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Client library (if applicable):

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'ros2 doctor --report' output

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Steps to reproduce issue

1. Create a message package pkg containing a message type named Duration with a field of type builtin_interfaces/Duration.
2. Compile the workspace and inspect the generated Python code.
3. Run mypy tests and flake8

Expected behavior

Message type pkg/Duration should be valid.

Actual behavior

The generated message Python code is invalid:

 27: /root/target_ws/build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py:87:1: F811 redefinition of unused 'Duration' from line 20
  27: class Duration(rosidl_pycommon.interface_base_classes.BaseMessage, metaclass=Metaclass_Duration):
  27: ^
  27: 
  27: 1     F811 redefinition of unused 'Duration' from line 20

  30: /root/target_ws/build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py:87:1: error: Name "Duration" already defined (possibly by an import)  [no-redef]
  30: /root/target_ws/build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py: note: In member "__eq__" of class "Duration":
  30: /root/target_ws/build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py:151:27: error: "Duration" has no attribute "header"  [attr-defined]
  30: /root/target_ws/build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py:153:25: error: "Duration" has no attribute "data"  [attr-defined]
  30: Found 3 errors in 1 file (checked 46 source files)

Additional information

Indeed, there are multiple places in the generated code that do:

from a.msg import b

But if the message is named pkg.Duration and the type of one of its fields is builtin_interfaces.Duration, then this import shadows the actual pkg.Duration and the code gets either confused, or even invalid.

I think all usages of from a.msg import b should be replaced by import a.msg; .... a.msg.b in the generated code. This way, the name collisions would not happen.

Reproduce the issue with a message package containing pkg/Duration and a builtin_interfaces/Duration field, then inspect the generated build/stamped_msgs/rosidl_generator_py/stamped_msgs/msg/_duration.py output. Trace the generator code that produces the conflicting imports, update the generation behavior so the message name is not shadowed, and run the reported mypy and flake8 checks to confirm the generated code is valid.