Add nightly check against known semantic convention repos and examples

[lmolkova]

Runs the weaver built from this working tree against the weaver-driven CI checks of the repos that consume it, so breaking changes surface before a release. Repos and checks are declared in downstream-check.yaml, used by both just downstream-check and the nightly workflow.

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Waiting on reviewers · refreshed 2026-08-05 19:38 UTC

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.4%. Comparing base (702f2d6) to head (50d2208).

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1672     +/-   ##
=======================================
- Coverage   81.4%   81.4%   -0.1%     
=======================================
  Files        131     131             
  Lines      11714   11714             
=======================================
- Hits        9539    9538      -1     
- Misses      2175    2176      +1     

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[Copilot]

Pull request overview

Adds a nightly (and on-demand) “downstream check” that builds Weaver from this repo and runs a curated set of Weaver-driven checks in downstream repositories, so breaking changes are detected before release.

Changes:

• Introduces cargo xtask downstream-check to clone downstream repos and execute configured checks with timeouts and a summary.
• Adds downstream-check.yaml as the single source of truth for downstream repos/refs/check commands (shared by local just and the nightly workflow).
• Adds a Downstream Check GitHub Actions workflow plus contributing docs and a just downstream-check entry point.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
justfile	Adds a just downstream-check wrapper over the new xtask.
downstream-check.yaml	Declares the downstream repos and the weaver-driven checks to run in each.
crates/xtask/src/main.rs	Wires a new downstream-check subcommand into xtask dispatch and help text.
crates/xtask/src/downstream.rs	Implements cloning, selection, execution, timeouts, and reporting for downstream checks.
crates/xtask/Cargo.toml	Adds serde/serde_yaml deps needed to parse the YAML config.
CONTRIBUTING.md	Documents how to run downstream checks locally and what the nightly does.
Cargo.lock	Locks new serde/serde_yaml transitive dependencies for xtask.
.github/workflows/downstream-check.yml	Adds the nightly/dispatch workflow and a tracking-issue reporter job.

Suppressed comments (2)

crates/xtask/src/downstream.rs:446

• On timeout, this unconditionally calls kill_group(...) (Unix-only) and relies on the external kill command. To keep xtask portable enough to compile on Windows/macOS, gate the Unix path and fall back to child.kill() on non-Unix platforms.

        }
        if Instant::now() >= deadline {
            eprintln!("!!! timed out, killing the check");
            kill_check(&mut child);

crates/xtask/src/downstream.rs:456

• kill_group is inherently Unix-specific (spawns the kill command and targets a process group). Once the timeout path is cfg-gated, this function should also be #[cfg(unix)] so the crate still compiles on non-Unix platforms.

/// Signals the whole process group of a check, so anything it spawned dies too.
#[cfg(all(unix, not(tarpaulin_include)))]
fn kill_check(child: &mut Child) {

---

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