ci-churn

name	ci-churn
description	Measure CI churn cost for a pull request: how many commits and how many CI-compute seconds were burned on avoidable "fix the CI" push rounds. Use when you want to understand the efficiency cost of a PR's iteration cycle, get actionable pre-push check suggestions, or include a churn summary in a pipeline report. Triggers: "ci churn", "how much CI did we burn", "avoidable commits", "ci efficiency", "wasted CI time", "churn report", "/ci-churn". Called automatically by /fp-drift at pipeline close.
version	1.0.0

ci-churn — CI Efficiency Report

Measure how many commits and CI-compute seconds were spent on avoidable "fix the CI" push rounds for a pull request, and surface the pre-push checks that would have prevented them.

Install

bash <(curl -sL https://raw.githubusercontent.com/gaia-research/skill-ci-churn/main/install.sh)

See README.md for gaia, npx skills, and manual install alternatives.

When to use

• At the end of any feature pipeline run (/fp-drift calls this automatically)
• Standalone after any PR you want to audit for iteration efficiency
• As a retrospective tool: "we spent N minutes of CI compute on churn"

How it works

1. Commit classification

Every commit in the PR is classified by its subject line:

Label	Pattern examples	Meaning
feature	feat(...), add ..., refactor ...	Intentional work
review-fix	per review, address review findings	Fixed after code review
ci-fix	fix import, restore export, codeql, lazy-import, wheel smoke	Fixed because CI caught something locally-detectable

feature commits are the signal. ci-fix and review-fix are churn.

2. CI duration fetch

For each commit SHA, the GitHub Actions API is queried for every workflow run triggered by that push. Duration is computed as updated_at − run_started_at (no run_duration_ms field exists in the API).

3. Metrics computed

Metric	Formula
Churn ratio	avoidable_commits / total_commits
CI compute burned	Sum of all run durations on avoidable commits
Agent blocked-wait (min)	Sum of failed run durations — the minimum time the agent was blocked waiting for bad results
Agent blocked-wait (max)	Same as CI compute burned — the agent also waited during the fix runs
Session time	Parsed from --session-log if provided (pi/claude-code JSONL)

4. Root cause hints

Based on which ci-fix commit messages matched which patterns, the script suggests concrete local pre-push checks that would have caught the same failure before it hit CI.

Run it

# Basic — auto-detects repo from git remote
python3 ci_churn.py <pr-number>

# With session log for agent time estimate (pi or claude-code JSONL)
python3 ci_churn.py <pr-number> --session-log ~/.pi/sessions/latest.jsonl

# Machine-readable JSON output
python3 ci_churn.py <pr-number> --json

# Explicit repo
python3 ci_churn.py <pr-number> --owner myorg --repo myrepo

Reading the output

CI Churn Report — PR #1017  (gaia-research/gaia-skill-tree)
════════════════════════════════════════════════════════

Commits: 5 total  (1 feature · 1 review-fix · 3 ci-fix)
Churn ratio: 80.0%  (4 of 5 commits were avoidable)

CI compute burned on avoidable commits : 22m 49s
CI compute on failed runs (all commits): 4m 16s
Agent blocked-wait estimate (min / max): 4m 16s / 22m 49s

Commit breakdown
────────────────────────────────────────────────────────
      SHA  Label         CI (s)  Fails  Message
─────────  ────────────  ──────  ─────  ─────────────────────────────────
5f418b26b  feature            0      0  feat(intake): batch skill intake…
ff99b6165  △ review-fix     187      2  fix(intake): address review findings…
3f3f98776  ⚠ ci-fix         391      1  fix(prWriter): restore open_pr export…
e1b612175  ⚠ ci-fix         398      0  fix(pushFromFile): lazy-import yaml…
78e0028b5  ⚠ ci-fix         393      0  fix(pushFromFile): replace substring…

Suggested local pre-push checks
────────────────────────────────────────────────────────
  • python3 -c "from gaia_cli.main import main"   # import chain smoke test
  • python3 -m pytest tests/ -x -q --timeout=30   # fast local test gate
  • bandit -r src/ -ll                             # security lint (CodeQL class)

Interpreting churn ratio

Ratio	Signal
0%	Perfect — every commit was intentional feature work
1–20%	Healthy — minor CI surprises, typical for new code paths
20–50%	Elevated — pre-push checks are missing or not being run
>50%	High churn — the local development loop is not catching what CI catches

Optional: session log integration

If you pass --session-log PATH, the script parses durationMs (pi) or duration_ms (claude-code) fields from assistant turns in the JSONL log and reports total agent session time alongside CI compute. This lets you answer: "of the N minutes this agent spent on this PR, how many were blocked waiting for CI results on avoidable failures?"

Session log paths:

• pi: ~/.pi/sessions/<project>/<session-id>.jsonl (check pi session ls)
• claude-code: ~/.claude/projects/<project>/<session-id>.jsonl

Notes

• run_started_at → updated_at delta is used because the GitHub Actions API has no run_duration_ms field. This slightly over-counts (includes queue time), but is consistent across all runs.
• The first commit on a PR branch often has 0 runs because CI hadn't fired yet when the PR was opened — this is expected, not a bug.
• gaia push --from-file, gaia dev add, and pure tooling PRs will almost always show 0 feature commits and high churn ratios. That is accurate — the entire PR was iteration cost, not new capability.