pytest-dev/pluggy

Avoid erroring from tracing

astrojuanlu opened this issue · 4 comments

astrojuanlu commented

A user reported a weird condition in which pluggy tracing was making their code fail after we enabled tracing because one of the local objects didn't have a working __repr__ (a scikit-learn object from a very old version). Details: kedro-org/kedro#2630

We gave the user a workaround and also it's reasonable to expect that objects have a working __repr__, but it would be nice if there was a generous try ... except around the tracing messages so that errors there don't bubble up. Essentially the same that happens with logging:

>>> try:
...   logging.warning("Will fail: %d", "a")
...   logging.warning("But the show must go on")
... except:
...   logging.error("Oh no")
... else:
...   logging.warning("Everything is fine")
... 
--- Logging error ---
Traceback (most recent call last):
  File "/opt/homebrew/Cellar/python@3.11/3.11.4/Frameworks/Python.framework/Versions/3.11/lib/python3.11/logging/__init__.py", line 1110, in emit
    msg = self.format(record)
          ^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.4/Frameworks/Python.framework/Versions/3.11/lib/python3.11/logging/__init__.py", line 953, in format
    return fmt.format(record)
           ^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.4/Frameworks/Python.framework/Versions/3.11/lib/python3.11/logging/__init__.py", line 687, in format
    record.message = record.getMessage()
                     ^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.4/Frameworks/Python.framework/Versions/3.11/lib/python3.11/logging/__init__.py", line 377, in getMessage
    msg = msg % self.args
          ~~~~^~~~~~~~~~~
TypeError: %d format: a real number is required, not str
Call stack:
  File "<stdin>", line 2, in <module>
Message: 'Will fail: %d'
Arguments: ('a',)
WARNING:root:But the show must go on
WARNING:root:Everything is fine
RonnyPfannschmidt commented

Let's steal the safe repr from pytest

  • 👍1
astrojuanlu commented

@RonnyPfannschmidt You mean saferepr and SafeRepr, right?

https://github.com/pytest-dev/pytest/blob/73d754bd74ae8ddf86eb90cda29545cef495e927/src/_pytest/_io/saferepr.py#L102-L115

Is this open for PRs? Any guidance on where the code should go is much appreciated.

RonnyPfannschmidt commented

Absolutely

RonnyPfannschmidt commented

For now it can just go to the private tracing module

  • 👍1