Save a reference to created async tasks, to avoid tasks potentially disappearing

[anio]

Save a reference to the result of this function, to avoid a task disappearing mid-execution. The event loop only keeps weak references to tasks. A task that isn’t referenced elsewhere may get garbage collected at any time, even before it’s done.

python docs

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Description of change

Please review the link: https://textual.textualize.io/blog/2023/02/11/the-heisenbug-lurking-in-your-async-code/

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Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01% ⚠️

Comparison is base (012f7cf) 91.38% compared to head (a7b45d7) 91.37%.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2816      +/-   ##
==========================================
- Coverage   91.38%   91.37%   -0.01%     
==========================================
  Files         126      126              
  Lines       32469    32469              
==========================================
- Hits        29671    29669       -2     
- Misses       2798     2800       +2     

Files Changed	Coverage Δ
redis/asyncio/cluster.py	91.66% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[jakob-keller]

@anio: Thanks for bringing the issue up!

I am not convinced that the fix is appropriate, though. As the source you provide mentions:

The solution recommended in the docs is to keep a reference to the task for as long as you need it to live.

The way I understand it is, that we need to save the task reference beyond the scope of the local / loop variable. As it stands, the reference will be lost almost immediately, rendering the fix ineffective.