From acd724079a5a41f2769da3422b27c4c61c7432bf Mon Sep 17 00:00:00 2001
From: "Claude (agent-stats)" <el-github@elangley.org>
Date: Thu, 24 Sep 2026 20:51:04 -0700
Subject: [PATCH] ci: run the repo-stats suite and a report-only push step in
 nix-build (improvise-1xfb.5.1)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze
---
 .github/workflows/ci.yml | 27 ++++++++++++++++++++++++++-
 scripts/checkers.sh      |  2 ++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1dd44856..9544b2d5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -146,13 +146,38 @@ jobs:
   # dependency crate each run. The NixOS runners substitute from titan's
   # harmonia first, and titan builds gh/main's `#improvise` hourly, so a PR that
   # leaves Cargo.lock alone rebuilds only the workspace crates it changed.
+  #
+  # The repo-stats pipeline runs here because it needs this job's binary:
+  # `nix shell .#improvise` reuses the build above instead of a second one.
+  # Its suite gates; the report on a push to main never fails the build, and
+  # its step fails only when improvise refuses the pipeline's input
+  # (context/code/tooling.md section 7). Full history is for the report.
   nix-build:
-    name: Nix build (crate2nix)
+    name: Nix build (crate2nix) and the repo-stats pipeline
     runs-on: [self-hosted, nixos, microvm]
     steps:
       - uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
       - name: nix build .#improvise
         run: nix build --print-build-logs .#improvise
+      - name: The repo-stats pipeline computes what it claims to
+        run: nix shell .#improvise --command ./scripts/checkers.sh --ci nix-build
+      - name: Churn, coupling and doc-growth report (report only)
+        if: github.event_name == 'push'
+        continue-on-error: true
+        run: |
+          rc=0
+          nix shell .#improvise --command ./scripts/repo-stats --out repo-stats > repo-stats.txt || rc=$?
+          { echo '```'; cat repo-stats.txt; echo '```'; } >> "$GITHUB_STEP_SUMMARY"
+          exit "$rc"
+      - name: Upload the repo-stats model and its CSVs
+        if: github.event_name == 'push'
+        uses: actions/upload-artifact@v7
+        with:
+          name: repo-stats
+          path: repo-stats
+          retention-days: 30
 
   wasm:
     name: wasm32 check (browser bundle crates)
diff --git a/scripts/checkers.sh b/scripts/checkers.sh
index bf837508..0a345c9b 100755
--- a/scripts/checkers.sh
+++ b/scripts/checkers.sh
@@ -101,6 +101,8 @@ ci_suites() {
   case "$1" in
     build) echo assemble-stamp ;;
     js) echo node-test ;;
+    # Needs the improvise binary, which only this job builds (tooling.md section 7).
+    nix-build) echo repo-stats ;;
     # check-harness-lock must never read "could not resolve" as "stale" (improvise-zs2r).
     kb) echo kb checkers pr-watch release-preflight pr-reviews fmt-workspaces bd-audit-ids check-harness-lock ;;
     *) return 1 ;;