Incorporate feedback on pipelines

[zimmy87]

Some of the logic in this repository's CI pipelines recently received a copilot code review in a context outside of this repository, and a portion of the feedback is applicable to this repository. This change applies that feedback.

Changes include:

• xtask/src/build.rs
  • remove unsafe std::env::set_var() call and replace with safe xshell::Shell::set_var() call
• xtask/src/clang_format.rs
  • remove explicit specification of "std::io::*" namespace due to already being imported
  • normalize path separators in is_excluded()
  • propagate clang-format exit status when --in-place is used
• xtask/src/clippy.rs
  • always run clippy on workspace
• xtask/src/coverage_report.rs
  • fix incorrect comment
• xtask/src/nextest_report.rs
  • use append logic when writing to GITHUB_OUTPUT
• xtask/src/precheck.rs
  • simplify subtask calls by adding more targeted imports
  • add extra clarification in comments
• xtask/src/rustup_component_add.rs
  • fix incorrect comment

[Copilot]

Pull request overview

This PR updates the xtask-based CI/pipeline helpers to incorporate review feedback, improving safety, portability, and consistency of various repo automation steps.

Changes:

• Replace process-global env mutation in build with xshell::Shell::set_var.
• Improve formatting/CI helpers: path normalization and exit-status handling in clang_format, always run clippy on the workspace, and append outputs for GitHub Actions report tasks.
• Refactor precheck subtask invocation for simpler, more direct calls and clarify comments.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
xtask/src/build.rs	Use Shell::set_var for RUSTFLAGS instead of std::env::set_var.
xtask/src/clang_format.rs	Use imported stdout(), normalize separators in excludes, and surface clang-format failures in --in-place mode.
xtask/src/clippy.rs	Ensure clippy runs against the full workspace consistently.
xtask/src/coverage_report.rs	Correct module-level doc comment to match JSON-based coverage input.
xtask/src/nextest_report.rs	Append to GITHUB_OUTPUT rather than overwriting it.
xtask/src/precheck.rs	Use targeted imports and inline task construction + execution; add clarifying comments.
xtask/src/rustup_component_add.rs	Fix struct field doc comment wording.

---

You can also share your feedback on Copilot code review. Take the survey.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

---

You can also share your feedback on Copilot code review. Take the survey.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

---

You can also share your feedback on Copilot code review. Take the survey.

[Copilot]

The clippy implementation now always runs with --workspace, but this README line still documents the command as cargo clippy --all-targets. Please update the documentation to reflect the actual invocation (e.g., mention --workspace, or describe it in a way that remains accurate if flags change again).

Suggested change

	- **clippy**: Runs `cargo clippy --all-targets` with warnings treated as errors
	- **clippy**: Runs Clippy across the entire workspace (all targets) with warnings treated as errors

[Copilot]

Section header has a typo: "Precheckin" should be "Prechecking".

Suggested change

	## Precheckin Steps
	## Prechecking Steps