SettingWithCopyWarning in job manager

[soxofaan]

reported by Joris C:

Not sure whether it's due to a change in the job manager, or whether it was there already, but I'm getting a warning on the line here:
https://github.com/Open-EO/openeo-python-client/blob/master/openeo/extra/job_management.py#L650
SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead
See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
active.loc[i, "running_start_time"] = rfc3339.utcnow()

[soxofaan]

I already looked into this issue, but I could not yet reproduce this warning from using the job manager.

I can reproduce it with some simple pandas usage like

df = pandas.DataFrame({"foo": range(10)})
active = df[df.foo % 3 == 0]
active.loc[3, "foo"] = 666

but I would need a more practical usage example of the job manager that triggers this

[soxofaan]

I could somehow reproduce the problem and 803fa2b seems to fix it. Unfortunately I didn't find a way to capture it in a unit test (because I could only reproduce it by hacks I don't want to keep in the code, and I couldn't wrap my head around the exact conditions that trigger the warning), so I'll just merge this and close this ticket. Will be part of next release (0.35.0). Feel free to reopen when problem persists