fix to inconsistent task instance state log message

[mchalek]

Dear Airflow maintainers,

This is a trivial fix to an incorrectly-formatted log message that we have been seeing in our logs. Please accept it without the usual JIRA + tests + etc due to its triviality.

Kevin

[codecov-io]

Codecov Report

Merging #2823 into master will increase coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2823      +/-   ##
==========================================
+ Coverage   73.84%   73.92%   +0.08%     
==========================================
  Files         159      159              
  Lines       12076    12076              
==========================================
+ Hits         8917     8927      +10     
+ Misses       3159     3149      -10

Impacted Files	Coverage Δ
airflow/jobs.py	79.69% <ø> (+0.44%)	⬆️
airflow/models.py	87.31% <0%> (-0.05%)	⬇️
airflow/utils/helpers.py	56.32% <0%> (+2.87%)	⬆️
airflow/task_runner/bash_task_runner.py	100% <0%> (+6.66%)	⬆️

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[Fokko]

Hi @mchalek, thank you for your contribution. Would it be possible to change it the other way around. We started moving to the %s format recently. Cheers

[mchalek]

hi @Fokko sure, I'll change it now. But, well not that it's my business, but isn't switching to %s kind of taking a step backwards? The python docs recommend .format() for new code: https://docs.python.org/2/library/stdtypes.html#str.format

I suspect the reasoning could be for compatibility with the log formatter that airflow is using?

[bolkedebruin]

@mchalek it doesn't say that. It says it is preferred for formatting strings (and thus not logging per se). However, if you want to use lazy logging you need to use %

Strike that. @Fokko please reconsider, this is string formatting not logging. .format should be used here imho.

[mchalek]

hi @bolkedebruin thanks for clarifying. It's too bad that the logger class does not support the new-style of formatting.

[ron819]

Is this still needed?

[mchalek]

@ron819 it looks like someone else fixed it. i will close this PR.