Add dtrace worker tag support

[stratakis]

No description provided.

[encukou]

This is how I'd do it. Maybe the branch logic could be elsewhere, but "dtrace is installed" is a feature of the worker, and I think tags are great for such features.

[encukou]

I generally want to move to using tags for configure options -- but mostly builder tags: e.g. having separate factories for Windows64PGONoGilTailcallBuild and all the other combinations of PGO/NoGil/Tailcall aren't a good use of subclassing.

Does that look like a good direction?

[stratakis]

I generally want to move to using tags for configure options -- but mostly builder tags: e.g. having separate factories for Windows64PGONoGilTailcallBuild and all the other combinations of PGO/NoGil/Tailcall aren't a good use of subclassing.

Does that look like a good direction?

For me it does sound that it;s a proper direction as it would reduce a lot of subclassing, given of course that an option to do extra customizations without much hassle will be there.

[vstinner]

LGTM.

So dtrace is not enabled on RHEL8 workers. DTrace doesn't work on RHEL8?

[stratakis]

LGTM.

So dtrace is not enabled on RHEL8 workers. DTrace doesn't work on RHEL8?

It should but the upstream fix is on 3.15+, RHEL8 workers test up to 3.12.

[stratakis]

Converted to a draft, there is an issue with the probes on shared builds when running the tests. Granted the test needs sudo or systemtap permission but I'd rather have this fixed first than risk buildbots failing unexpectedly.