Improved the test error messages when 'rustc -V' fails - #17108
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weihanglo merged 1 commit intoJun 17, 2026
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| if exit_code != Some(0) { | ||
| let stdout = std::str::from_utf8(&output.stdout).unwrap_or("<invalid utf8>"); | ||
| let stderr = std::str::from_utf8(&output.stderr).unwrap_or("<invalid utf8>"); | ||
| let extra = if exit_code.map(|c| c as u32) == Some(3221225495) { |
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I believe this is generally written in hex
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| let extra = if exit_code.map(|c| c as u32) == Some(3221225495) { | |
| let extra = if exit_code.map(|c| c as u32) == Some(0xC0000017) { |
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I dislike having the constant but unsure if it is worth pulling in windows-sys to get the constant
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Could we have a comment link to the official doc about this exit code?
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I updated to 0xC0000017. I felt pulling in windows-sys was a bit overkill for a slightly better error message in what I expect to be a rare failure.
Also it seems like this error code is not well documented.
I can see many blog posts about "how to fix windows booting" that mention this error code but could not track down any official documentation on this code 😅
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Update cargo submodule 7 commits in fe63976b245b8a649c3f2949bf89fdc307bfbae4..598ab48ec328e3e4f5e4e373d8df7264bc8e27cd 2026-06-11 09:17:57 +0000 to 2026-06-17 02:39:50 +0000 - Improved the test error messages when 'rustc -V' fails (rust-lang/cargo#17108) - test(install): `cargo install` --path honors MSRV (rust-lang/cargo#17102) - feat(trim-paths): emit `CARGO_TRIM_PATHS_REMAP` for build.rs (rust-lang/cargo#17104) - Add funding links (rust-lang/cargo#17103) - fix(diag): Give diagnostics the same display path behavior as rustc (rust-lang/cargo#17101) - refactor: remove cargo-util-terminal from bump-check exclusions (rust-lang/cargo#17098) - fix(diag): Report all errors, in order (rust-lang/cargo#17095)
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What does this PR try to resolve?
While debugging the build issues in rust-lang/rust#155439 I was running into some issues where
rustc -Vwould fail due to windows path limits.When happens the error message is not super helpful.
I added some panic messages which replace the currently less helpful
help:line.I also special cased Windows error code
3221225495with a dedicated error message since is its not super obvious what is happening I hope to avoid other having to go through the pain of debugging this.How to test and review this PR?
I tested against the changes in rust-lang/rust#155439 but you could also probably override the rustc on the PATH with something that always returns an error status code.
r? @weihanglo