Fix setting of tracing variables

[ribice]

Perhaps we should also do type checks?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.29%. Comparing base (9311a06) to head (6607bd0).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #806      +/-   ##
==========================================
+ Coverage   81.08%   81.29%   +0.20%     
==========================================
  Files          49       49              
  Lines        4087     4090       +3     
==========================================
+ Hits         3314     3325      +11     
+ Misses        632      628       -4     
+ Partials      141      137       -4     

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[vaind]

Can you also add a test case that fails before the code changes are applied.

Perhaps we should also do type checks?

yes, I agree. Maybe move the type cast to the condition.