[libcxx-commits] [libcxx] Add option for verbose output from `run-buildbot`. Disable by default. (PR #144704)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne commented:

I'm not sure this buys us that much. Compare for example:

Without verbose (your patch): https://github.com/llvm/llvm-project/actions/runs/15734663895/job/44362585390?pr=144704

Before your patch: https://github.com/llvm/llvm-project/actions/runs/15674865342/job/44354780295?pr=144310

If you go under "Build and test", we already collapse into sections so it looks like this before expansion:
<img width="1742" alt="Screenshot 2025-06-20 at 12 25 06" src="https://github.com/user-attachments/assets/ee8ff182-a2eb-4af8-8f24-88378516f2d3" />

Then, when you expand e.g. `Running libc++ tests`, in both cases you get this:
<img width="1555" alt="Screenshot 2025-06-20 at 12 26 20" src="https://github.com/user-attachments/assets/b996a824-33cf-4a51-b5cc-dde3e85e5afb" />

This is not super succinct but it shows how the test suite is set up, and in particular there is no noise like headers being installed or similar.

The difference is when you expand `Building libc++ test dependencies`, where you get the super verbose output before your patch, and not much information after your patch. In particular, we lose the command-lines used to compile each translation unit in the library, which is likely of interest for someone expanding that section of the CI logs.

So, TLDR, since we already have collapsed-by-default sections in the CI logs, I'm not convinced this patch buys us much, but we do lose some useful information. WDYT?

https://github.com/llvm/llvm-project/pull/144704