How do you debug embedded python (Docker Container) in VSCode

Hi @John McBride. We don't currently support formal debugging for embedded Python, so you won't be able to set breakpoints, etc. We're working on this high priority functionality.

Hi John, 

As Raj suggested, we don't currently support debugging in vscode. However, if you are open to interactively debugging from terminal, here're some ideas.

1. If you have a specific part of code you're interested in, I'd recommend manually setting breakpoint() or import pdb; pdb.set_trace() in your python code. When hitting these lines, pdb will pause the execution of your Python code and drop you into an interactive debugging session. This allows you to inspect variables, evaluate expressions, and step through your code line by line to better understand its behavior and identify any issues. See here for how to use pdb commands.

Caveat 1: For the python code defined in an ObjectScript file with [ Language = python ], you won't be able to see python the source code when running list (which is a useful pdb command). This is due to Python linecache module only picking up regular files on your filesystem whereas [ Language = python ] stores the code in the ^ROUTINE global.

Caveat 2: If your Python method A calls into an objectscript method B, which calls into another Python method C, this will leave you at the "A" level of call stack. You can't cross the line between Python stack frame to ObjectScript stack frame using pdb. But you can move between adjacent Python stack frames.  

2. If you don't know where you want to start debugging and only want to inspect the state of python after it fails, you can try this internal API, (not guaranteed to work in the future)

Do $System.Python.Debugging(1)
Do ##class(YourClass).YourMethod()
Set pdb = $System.Python.Import("pdb")
Do pdb.pm()

This also drop you into an interactive pdb debugging session of the last error. You still have the caveats described above.

Just to clarify,

Do $System.Python.Debugging(1)

Will end up causing the C piece of SW that translates IRIS to python to call this:

In practice what this means, is somewhere close to your exception this gets called:

After your exception.