[ci] Run tests under Valgrind Ubuntu x86

[mcbarton]

Description

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Fixes # (issue)

Type of change

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• Bug fix
• New feature
• Added/removed dependencies
• Required documentation updates

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.05%. Comparing base (5860e95) to head (d47866d).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #405   +/-   ##
=======================================
  Coverage   82.05%   82.05%           
=======================================
  Files          21       21           
  Lines         858      858           
  Branches       89       89           
=======================================
  Hits          704      704           
  Misses        154      154           

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[mcbarton]

I am not sure what is going wrong with using Valgrind on Ubuntu arm runners in the ci (see https://github.com/compiler-research/xeus-cpp/actions/runs/19150317221/job/54738556792?pr=405 ) . This Valgrind error doesn't occur when I run same command locally (and how I managed to produce the Valgrind suppression file. I don't know how to interpret the suppression files, so unsure if there is anything in there that we don't want to suppress.

[anutosh491]

Why is this PR needed in the first place ?

P.S : Asking as someone who is clueless about Valgrind.

[mcbarton]

Why is this PR needed in the first place ?

P.S : Asking as someone who is clueless about Valgrind.

The truthfull reason as to why I added this to the ci is to be consistent with all of compiler researches other repos, which run the tests under Valgrind. I cannot list the benefits of Valgrind as I am still in the process of teaching myself how to use it effectively. I for example cannot tell you if I am suppressing anything that we shouldn't. @vgvassilev @Vipul-Cariappa or @aaronj0 though may be able to enlighten you as to why its used in all the other repos, and help you with a review (once they have bandwidth).

I have limited this PR to just running the tests under Valgrind for Ubuntu x86, as running the tests under Valgrind on Ubuntu arm caused an illegal instruction error from Valgrind which doesn't happen locally, so possibly a bug with the runner. I consider this PR now ready for review.