Pyblish Plugins Debugging

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Hello awesome community and fellow developers,

Debugging is a key part of our everyday tasks, whether we’re troubleshooting a file in production or ironing out issues with a plugin during development.

1. Publisher’s Details tab

In the publisher UI, we have a Details tab where you can review the logs for each plugin individually. and you can always add as much log statements as you need.

However, You may find log statements quite limited if you’re looking for deeper insights. For example, understanding the changes in context or determining the execution time of the plugin…

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2. Pyblish Debug Stepper

The Pyblish Debug Stepper, developed by @BigRoy, serves precisely this purpose!
It provides a Step-by-Step Debugging, enabling you to examine plugins one at a time. At each step, it shows the context and instances along with their data.

It now exists as an experimental feature in AYON.
For reference, here’s the PR Experimental tool: Pyblish debug stepper #753 | Core Addon

Here’s a quick demo :wink:

3. Use Python Debuggers

This one is not much discussed and it has its own caveats.
More info about in comments.

And Keep Tinkering! :wink:

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The required logic to make this easier has been merged into pyblish-base with Add 'context' key to 'result' dict by MustafaJafar · Pull Request #401 · pyblish/pyblish-base · GitHub which made its way into the 1.8.12 release of Pyblish: Release 1.8.12 · pyblish/pyblish-base · GitHub

It would be great to update the Pyblish dependency in AYON which would make this feature/tool just that - a tool, instead of requiring the other customizations.

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Cool!

Related question, is there a typical workflow that others use for debugging plugins in their preferred IDE (PyCharm, VSC etc)?

From what I see, the only change needed to get this working (unless I’m mistaken - please point out!) is to compile the py file content prior to six.exec_ in pyblish.plugin.discover.

For example:

with open(abspath, 'rb') as f:
    source = f.read()
    code = compile(source, abspath, 'exec')
    six.exec_(code, module.__dict__)

Apologies if this is a stupid question, or perhaps not the best place.

Thanks,
Lee

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I believe actually since some code changes in Pyblish and upgrades to Py3 that debuggers should be able to run through Pyblish Plug-ins just fine. It’s been a while ago that I read that somewhere and can’t fidn details about it now.

There was this ancient topic but I definitely do recall running a “remote debug session” with Pycharm and it working fine to set breakpoints inside Pyblish plug-ins. This was maybe a year ago at most.

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Hey @ldunham1 ,
Thanks for expanding the topic!

For the first glance, I didn’t get it but the link that BigRoy’s shared explained it to me furtherly.

Summary, quoted from Marcus.
“You see when plug-ins are discovered on disk, they are loaded as a block of text, rather than imported directly. This is how they are able to reload themselves interactively. It’s possible this throws off any debugger.”

one of the replies suggested replacing the mentioned lines above by the following lines. and the debugger worked with that on their end.

try:
    module = imp.load_source(mod_name, abspath)
except Exception as err:
    log.debug("Skipped: \"%s\" (%s)", mod_name, err)
    continue
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Thanks for the replies both!
I thought I checked on 3.7 and it was still an issue - will try 3.10.

Otherwise, I suggested the compile option purely for ease of integration.
The issue with imp or importlib would be compatibility with python versions.

Out of interest, would there be any functional reason to prefer using an imp/importlib option over the compile?

(For my own sanity :wink:

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As far as I know,
exec is used for executing a dynamically created statement or program.
Compile compiles the source into a code which can speed up repeated invocations of the same code with exec or eval.

>>> program = '''
for i in range(3):
    print("Python is cool")
'''
>>> exec(program)
>>> exec(compile(program))  # Compile beforehand

Reference: python - What's the difference between eval, exec, and compile? - Stack Overflow

Anyways, your code snippet seems to do the same thing as pyblish. loading plugins as a block of text. which we suspect is respnosible for throwing of debuggers.

with open(abspath, 'rb') as f:
    source = f.read()
    code = compile(source, abspath, 'exec')
    six.exec_(code, module.__dict__)

This link is interesting

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This is likely best asked to Marcus (developer of Pyblish), e.g. on the pyblish forum or pyblish base issues. However, if you do so it might be worth to try and run the debugger again using latest Python. And if it still gives you issues, to then provide the “what you tried” information to pyblish-base issues to raise the questions and the issue you faced.

I recall there having been proposals for changes in the past - and there being accompanying discussions. But for the life of me, I can’t find any now.

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Yeah, I think the compile embeds the filepath so it can be used during debugging - the functional difference that seems to make it work (my side) as opposed to current implementation.

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Thanks, I’ll get some tests done on different versions and post for Marcus if I’m getting the same results.

Thanks again!

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@ldunham1 Any progress on your explorations?

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Hello @BigRoy and @mustafa_jafar, Thank you for the awesome guide.

I’m currently trying the PyBlish Debug Stepper in Maya 2024.2. However, I kept encountering this error in when I try to publish. Please advise.

# # Traceback (most recent call last):
#   File "C:\Users\atu\AppData\Local\Ynput\AYON\dependency_packages\ayon_2406251801_windows.zip\dependencies\pyblish\lib.py", line 273, in emit
#     callback(**kwargs)
#   File "<maya console>", line 144, in on_plugin_processed
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 172, in deepcopy
#     y = _reconstruct(x, memo, *rv)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 297, in _reconstruct
#     value = deepcopy(value, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 172, in deepcopy
#     y = _reconstruct(x, memo, *rv)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 271, in _reconstruct
#     state = deepcopy(state, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 146, in deepcopy
#     y = copier(x, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 231, in _deepcopy_dict
#     y[deepcopy(key, memo)] = deepcopy(value, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 172, in deepcopy
#     y = _reconstruct(x, memo, *rv)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 271, in _reconstruct
#     state = deepcopy(state, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 146, in deepcopy
#     y = copier(x, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 231, in _deepcopy_dict
#     y[deepcopy(key, memo)] = deepcopy(value, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 146, in deepcopy
#     y = copier(x, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 231, in _deepcopy_dict
#     y[deepcopy(key, memo)] = deepcopy(value, memo)
#   File "C:\Program Files\Autodesk\Maya2024\Python\lib\copy.py", line 161, in deepcopy
#     rv = reductor(4)
TypeError: cannot pickle 'PyCapsule' object
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Not entirely sure which code you used exactly, but there’s a copy.deepcopy occurring SOMEWHERE in that code where the deepcopy fails on a certain Python object.

This has been fixed in this implementation here but not sure if that’s similar in the code you used.

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Hi @BigRoy, I used the version from the original thread here Pyblish debug stepper - pauses between each plug-in process and shows the Context + Instances with their data at that point in time · GitHub

I’m so glad that this tool is in AYON Core now =)).

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So did you get it to work using that one? :heart_hands:

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It work like a charm.

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1 Like
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Great to hear!
Could you please add your feedback as a review/comment in this PR Feature/add pyblish debug stepper to experimental tools by MustafaJafar · Pull Request #753 · ynput/ayon-core · GitHub ?

2 Likes