diagnose-ci-failures
Programmatically diagnose CI failures for a PR and generate a plan to fix them.
Overview
This skill provides a deterministic workflow to check CI status for a PR, extract failure logs, analyze errors, and create a plan (not code changes) to resolve issues. The output is always a plan document that can be reviewed before execution.
Workflow
1. Verify PR exists for current branch
Get the current branch and check if a PR exists:
bash
# Get current branch
git branch --show-current
# Check for PR
gh --no-pager pr view <branch-name> --json number,title,url,state
If no PR exists, inform the user and offer to create one using the
skill.
2. Check CI status
Fetch the status of all CI checks:
bash
gh pr view <branch-name> --json statusCheckRollup
Parse the output to identify:
- Completed checks vs. in-progress checks
- Successful checks
- Failed checks with their names and details URLs
If CI is still running, inform the user which checks have already failed or passed, highlight the checks that are still running, and suggest waiting for completion before diagnosis.
3. Extract failure logs
For each failed check, pull the logs using the run ID from the status check:
bash
gh run view <run-id> --log-failed
Focus on extracting:
- Error messages and their locations (file paths, line numbers)
- Compilation errors (unused imports, type mismatches, etc.)
- Linting/clippy errors with specific lint names
- Test failure messages and stack traces
- Build failures and their root causes
4. Categorize errors
Group errors by type:
- Formatting issues: failures
- Linting issues: warnings/errors
- Compilation errors: Type errors, missing imports, signature mismatches
- Test failures: Failing tests with their names and failure reasons
- Platform-specific issues: WASM, Linux, macOS, Windows-specific failures
5. Generate fix plan
Create a plan document (using
tool) with:
- Problem Statement: Summary of failing checks
- Current State: What errors were found and where
- Proposed Changes: Specific fixes needed for each error category
- Validation Steps: Commands to verify fixes (fmt, clippy, tests, presubmit)
The plan should reference the
skill for detailed guidance on resolving specific error types.
Important Notes
- Always create a plan first: Never make code changes directly. Generate a plan for user review
- Check test status in CI: Even if tests fail locally, verify they passed in CI before flagging as issues
- Unrelated test failures: If tests passed in CI but fail locally, they may be environment-specific or flaky
- Multiple error types: Fix one category at a time (e.g., all clippy errors before tests)
- Cross-reference fix-errors skill: For detailed error resolution strategies, use the skill
Common CI Check Names
Formatting + Clippy (MacOS)
Formatting + Clippy (Linux)
- (summary check)
Example Commands
Get PR status with details:
bash
gh --no-pager pr view --json number,title,state,statusCheckRollup
Get logs from specific failed run:
bash
gh run view 12345678 --log-failed
Check for specific error in logs:
bash
gh run view 12345678 --log-failed 2>&1 | grep -A 5 "error:"