Python Debugging: Breakpoints are no longer hit in mixed C++/Python debugging in Visual Studio

[jckand]

Describe the bug Breakpoints are no longer hit in mixed C++/Python debugging in Visual Studio. As soon as the Editor is started via Visual Studio, any breakpoints set in Python files report that no symbols are loaded for the document.

Assets required

1. Python native development tools installed for Visual Studio.
2. Microsoft Child Process Debugging Power Tool extension installed and enabled for Visual Studio.

Steps to reproduce

1. Open any Python test file in Automated Testing and add a breakpoint.
2. Set the Editor to the startup project.
3. Enable the Python/Native Debugger.
4. Start the Editor.
5. Once loaded into the Editor, open the Python Console and run:

   azlmbr.legacy.general.run_file("[Full//path//to//python_test_file.py]")

   e.g.

   azlmbr.legacy.general.run_file("D:\\GitHub\\o3de\\AutomatedTesting\\Gem\\PythonTests\\Prefab\\tests\\spawnables\\Lua_Spawnables_SimpleSpawnAndDespawn.py")

Expected behavior Breakpoint is hit in Visual Studio when the Python file is executed.

Actual behavior Test script runs as normal with no breakpoints hit.

Screenshots/Video

Found in Branch development

Commit ID from o3de/o3de Repository c3fa0d4a8b199f60a01473b21ba77510c368ae27

[Kadino]

Both @jckand-amzn and @FuzzyCarterAWS can be reached out to for more information.

[Kadino]

Older issue which appears related: https://github.com/o3de/o3de/issues/7381

[Kadino]

Investigating by also following MSVS guide Mixed-mode debugging

[Kadino]

Reproduced this behavior on MSVS 2022 v17.5.0 in development at 9a99b1a388 Even manually attaching the python debugger did not hit breakpoints, despite the debugger stating it attached.

[Kadino]

Visual Studio is not automatically attaching the Python debugger, and the Editor project properties do not display an option for Python debugging. This may be related to MSVS project settings.

However launching and attempting to manually attach to the application shows it exposes Python debugger hooks:

The debugger does attach to something, though is unable to pause any executing code.

[Kadino]

Nothing I've tried made the "Python/Native Debugging" option enabled in the MSVS project settings. There was also no effect from setting the python environment in View > Other Windows > Python Environments nor from explicitly pointing MSVS at the python pdb's.

Interestingly, breakpoints set in the C++ function PyRunFile are not hit when invoking azlmbr.legacy.general.run_file. Instead the first C++ method seen is the call to PyIdleEnable invoked by the script. This suggests another method to execute scripts is being used, or that the symbols aren't available in profile builds. Regardless, the hunt for mixed-mode python debugging continues. Likely culprit remains the lack of "Python/Native Debugging" option.