Tracking Issue for `--crate-type` flag

[ehuss]

Summary

RFC: #3180
Implementation: #10093
Documentation: https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#crate-type

This is the tracking issue for RFC 3180 which adds the --crate-type argument to cargo rustc to explicitly change the crate type of the crate being built.

Unresolved Issues

No response

Future Extensions

No response

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.

[0xPoe]

I would like to try to add it. Can I claim it?

[ehuss]

Sure! I don't think anyone else has expressed interest.

Let me know if you have any questions. For handling unstable support, fail_if_stable_opt can be used to require -Z unstable-options.

I'm not sure about the best way to pass the information down to the right place. I'm thinking adding another map to BuildContext similar to extra_compiler_args might be a good option for now. Then the points where the crate-type is selected can consult that map to see if there is an override.

[seanmonstar]

I tried this out in hyper today, and hit errors. Filed #10356

[yodaldevoid]

Is making this feature stable on hold until the cargo team has additional review capacity? If not, what needs to happen to get this over the finish line?

I assume we just want to wait to see if anyone runs into more issues, but how long should we wait?