A guide to how rustc works and how to contribute to it.
C-Rank Grade: A (Welcoming) - 70/100
External PR Merge Rate: 68%
Response Time: <1h
First Timer Success: 60%
rust-lang/rustc-dev-guide has a recorded first-timer success rate of 60.0%. Repositories ranked A typically provide actionable feedback during code reviews and actively nurture new community contributors.
Maintainers in rust-lang/rustc-dev-guide respond to incoming external pull requests in approximately 0.7 hours on average. Keeping PRs focused on single tasks and ensuring tests pass helps maintainers review faster.
The C-Rank™ system evaluates GitHub projects on a 0–100 scale using real data: PR merge rates, review turnaround time, active maintainer presence, and first-time contributor success. A score of 69.7 places rust-lang/rustc-dev-guide in the A tier.
The external contributor pull request merge rate for rust-lang/rustc-dev-guide is 68.1%, based on public PR activity from non-core contributors.
rust-lang/rustc-dev-guide currently has 2 active issue(s) tagged with beginner-friendly labels like "good first issue", "beginner", or "up-for-grabs".
Collaborative maintainer environment in rust-lang/rustc-dev-guide. Reviews community pull requests with focus on project quality.
Discussions in rust-lang/rustc-dev-guide focus heavily on practical implementation feedback, code formatting standards, and issue reproduction details.
Unlinked PRs without issue context and changes that fail automated test suites face the highest review friction.
Average Response Latency
Tracks hours until a maintainer leaves a review, comment, or PR response.
External Acceptance Rate
Percentage of community pull requests successfully merged into main.
First PR Conversion
Rate at which developers submitting their first repository PR succeed.
Show contributors that your repository actively reviews and merges external pull requests.
[](https://getmerged.abhishekco.de/rust-lang/rustc-dev-guide?utm_source=github&utm_medium=badge)
Historical health & responsiveness evolution
External PR acceptance
First PR success rate
50% receive response in
90% receive response in
Maintainer review activity heatmap & prime window prediction
Calculating local time...
Calculating local time...
Detected: UTC
Maintainers are most responsive around 06:00 UTC (06:00 UTC in your timezone). Recommended submission window is Wednesday - Friday from 05:00 to 09:00 UTC (05:00 - 09:00 UTC local).
Maintainer Strategy: Maintainer Sweet Spot: PRs under 150 lines merge in ~4 hours (85% approval). Large PRs (>500 lines) take ~3 hours (31% approval). Keep your diff compact for rapid review.
Procedure Each of these dates should be checked to see if the docs they annotate are up-to-date. Each date should be updated (in the Markdown file where it appears) to use the current month (October 2026), or removed if the docs it annotates are not expected to fall out of date quickly. Please check off each date once a PR to update it (and, if applicable, its surrounding docs) has been merged. Please also mention that you are working on a particular set of dates so duplicate work is avoided. Finally, once all the dates have been updated, please close this issue. Dates src/backend/updating-llvm.md 2026-03 line 173 src/borrow-check/region-inference/member-constraints.md 2026-03 line 98 src/debuginfo/lldb-visualizers.md 2025-11 line 14 2025-11 line 118 2025-11 line 253 2025-11 line 285 2025-11 line 590 src/diagnostics/error-codes.md 2026-03 line 13 src/diagnostics/translation.md 2024-10 line 5 2024-10 line 11 src/feature-gate-check.md 2026-02 line 11 src/fuz
Procedure Each of these dates should be checked to see if the docs they annotate are up-to-date. Each date should be updated (in the Markdown file where it appears) to use the current month (September 2026), or removed if the docs it annotates are not expected to fall out of date quickly. Please check off each date once a PR to update it (and, if applicable, its surrounding docs) has been merged. Please also mention that you are working on a particular set of dates so duplicate work is avoided. Finally, once all the dates have been updated, please close this issue. Dates src/backend/updating-llvm.md 2026-03 line 173 src/borrow-check/region-inference/member-constraints.md 2026-03 line 98 src/debuginfo/lldb-visualizers.md 2025-11 line 14 2025-11 line 118 2025-11 line 253 2025-11 line 285 2025-11 line 590 src/diagnostics/error-codes.md 2026-03 line 13 src/diagnostics/translation.md 2024-10 line 5 2024-10 line 11 src/feature-gate-check.md 2026-02 line 11 src/f
Rate what actually matters after opening a pull request here.
Rate your first-hand PR experience (review speed, maintainer responsiveness, and onboarding ease) to help other contributors.
When evaluating whether to contribute to rust-lang/rustc-dev-guide, response velocity and maintainer engagement are crucial. GetMerged continuously tracks pull request trajectories, first-comment latency, and code review rounds to help developers avoid submitting pull requests to backlogged repositories.
Currently, maintainers of rust-lang/rustc-dev-guide acknowledge new external contributions in approximately <1 hour. Out of all submitted pull requests from non-core authors in the last 180-day window, 68.1% were successfully merged into the primary branch.
rust-lang/rustc-dev-guide has a recorded first-timer success rate of 60.0%. Repositories ranked Welcoming typically provide actionable feedback during code reviews and actively nurture new community contributors.
The initial maintainer response time averages ~<1 hour. Keeping PRs scoped to single concerns and ensuring CI checks succeed will optimize review turnaround.
The C-Rank™ index scores repositories on a 0 to 100 scale using an objective formula: external PR merge rates, initial response speed, active maintainer count, and first-time contributor retention. A score of 69.7 places rust-lang/rustc-dev-guide in the Welcoming tier.
The external pull request merge rate is 68.1%. GetMerged isolates non-core community contributions so external developers get an accurate benchmark of PR acceptance probability.
Yes, rust-lang/rustc-dev-guide currently has 2 active issue(s) tagged with beginner-friendly labels. You can inspect these directly from the repository issues tab.
All metrics displayed for rust-lang/rustc-dev-guide are automatically retrieved via the public GitHub API and recalculated daily. Insider pull requests submitted by repository owners or organization members are excluded from merge rate calculations to preserve objective external contributor statistics.