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Fix crash when expanding variables in post-mortem #465

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Fix crash when expanding variables in post-mortem #465

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6bfd17b
Fix crash when expanding variables in post-mortem
qhuy4119 Jul 14, 2021
99a32b6
Merge branch 'inducer:main' into fix-post-mortem-variable-crash
qhuy4119 Jul 18, 2021
b5f0dae
Use stack property to return a modified view of the stack in post_mortem
qhuy4119 Jul 18, 2021
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1 change: 1 addition & 0 deletions pudb/debugger.py
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Original file line number Diff line number Diff line change
Expand Up @@ -403,6 +403,7 @@ def interaction(self, frame, exc_tuple=None, show_exc_dialog=True):
self.stack, index = self.get_shortened_stack(frame, tb)

if self.post_mortem:
self.stack.append((self.bottom_frame, self.bottom_frame.f_lineno))
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@inducer inducer Jul 14, 2021 •
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How does pdb handle this situation? self.stack here is something that's managed by bdb, I'm not sure we're at liberty to modify it.

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@qhuy4119 qhuy4119 Jul 14, 2021 •
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After finishing the execution of the script, pdb enters this finally block (kinda like our post-mortem mode). At this point, if we type p <variable name> on the command line, pdb will print a NameError, and the user continues with the pdb REPL. So currently our IndexError is similar to this NameError.

I haven't dig into how bdb manages the stack in this case.

The problem with the current PuDB is that if I have an object at the module level, say a = list(range(100)) for example, I can't expand it in post-mortem to see what the elements are . This PR allows user to inspect data structures like that.

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@inducer inducer Jul 16, 2021

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Instead of modifying data structures that aren't ours to modify, could you instead create a @property that provides a modified view of the stack, and then change the relevant spots of the code to use that view of the stack instead? Also make sure to add comments to explain why this is being done.

index = len(self.stack)-1

self.set_frame_index(index)
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