Add an easier way of running `rustc --explain`

[oriongonza]

Problem

fn main() {
    hello
}

This errors with E0425. It would be nice if cargo offered a way to explain the error in depth!

error[E0425]: cannot find value `hello` in this scope
 --> src/main.rs:2:5
  |
2 |     hello
  |     ^^^^^ not found in this scope

For more information about this error, try `rustc --explain E0425`.
error: could not compile `tests` (bin "tests") due to 1 previous error

You can of course copy and paste the command but it would be nicer to not have to.

Proposed Solution

You could run cargo check --explain that opens up the help page for the given error.

Notes

No response

[weihanglo]

Are you proposing cargo --explain without a given error code should just check the latest error we've got?

[oriongonza]

More specifically, adding it to check, build, etc should do that if it encounters any explainable error.

Not sure what should happen for several errors.

[epage]

rustc has been exploring hyperlink support and having the error codes be a link to the relevant page seems the most useful. You could immediately click the link without having to go back in your history to re-run the command and then avoid that entry in your history when you want to run without it.

[oriongonza]

That would be even better indeed

[weihanglo]

@epage do you have any discussion we can link to? I think we can close this in favor of that then.

[epage]

I'm not aware of a tracking issue for the unstable feature

• MCP: Teach rustc to use OSC8 on nightly / Embedded links in terminal output compiler-team#587
• Initial work: Introduce -Zterminal-urls to use OSC8 for error codes rust#107838 (which looks to implement what I suggested)
• Zulip thread: https://rust-lang.zulipchat.com/#narrow/stream/147480-t-compiler.2Fwg-diagnostics/topic/Richer.20diagnostics.3F/near/430145899

[weihanglo]

Sounds good. Thanks and close in favor of those.

@dev-ardi feel free to join and discuss on Zulip :)