rustdoc: Tracking issue for command-line flag `--test-builder`

[ojeda]

FIXME: Write a proper synopsis.

Original description

The flag was added in the second commit of #64328, but I couldn't find a tracking issue (like #87022 for --no-run).

Is it meant to be stabilized?

• If yes: please feel free to reuse this as the tracking issue like in the --no-run one.
• If not: we are currently using it (together with --no-run) in the kernel to extract the source code of the tests, i.e. to achieve something similar to --persist-doctests, but for source code; or like --scrape-examples, but for doctests. Would there be a better/stable way to do that?

In the PR above [@]Mark-Simulacrum mentions:

This is largely intended for "advanced" users at this point (I'm not sure if we'll ever stabilize it)

[@]GuillaumeGomez

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.

Implementation history

• rustdoc: change doctests locating rustc binary #64328

[GuillaumeGomez]

I don't think it was intended for being stabilized.

[Mark-Simulacrum]

That PR tried to make it unstable (see the call to unstable in lib.rs), so we should track down the gap or PR that stabilized it.

[aDotInTheVoid]

Relevent zulip discussion on rust-for-linux's use of this to enable running doctests in kernelspace.