Tracking Issue for `-Zbuild-analysis`

[weihanglo]

Summary

Original issue: rust-lang/rust-project-goals#332
Documentation: https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#build-analysis
Project goal: rust-lang/rust-project-goals#398

The -Zbuild-analysis feature records and persists detailed build metrics (timings, rebuild reasons, etc.) across runs, with new commands to query past builds.

Considerations for stabilization

• Review the JSON schemas we exposed are reasonable (especially rebuild reason which has lots of variants)
• JSON schema evolution

Unresolved Issues

See the unresolved design questions in the design doc: https://hackmd.io/K5-sGEJeR5mLGsJLXqsHrw?view#Unresolved-questions.

Future Extensions

No response

Implementations

See the design doc: https://hackmd.io/K5-sGEJeR5mLGsJLXqsHrw

• Nightly feature gate and configuration feat(unstable): add -Zbuild-analysis unstable feature #15845
• Storage infrastructure, storage path, migration, etc. feat(build-analysis): JSONL-based logging infra #16150
• Collecting metrics
  • Collect build metadata feat(build-analysis): JSONL-based logging infra #16150
  • Collect CLI args (so people know what they've run)
  • Collect timing data timing-info event feat(build-analysis): emit timing-info log #16179
  • Collect rebuild reason data feat(build-analysis): emit rebuild reason log entry #16203
• Set up new unstable cargo report subcommands
  • cargo report timing
  • cargo report rebuild-reason
• benchmark the build performance impact

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.

[weihanglo]

Implementation tasks

See the PR description.