Greenhorn / captured contrast

Unconstrained Codex baseline.

A separate Codex session worked in a disposable copy of the same fixture. It was explicitly allowed to use ordinary developer knowledge to fill README gaps. This is not a Greenhorn run and receives no contract ruling.

The fixture is deliberately seeded. This capture proves a behavioral contrast only; it is not a prevalence result, a third-party-repository result, or an isolation benchmark. The baseline deliberately uses convenient host developer tools; Greenhorn’s accepted commands run in Docker.

Commands actually recorded

/bin/zsh -lc "pwd && rg --files -g 'README*' -g 'package.json' -g 'pnpm-lock.yaml' -g 'yarn.lock' -g 'package-lock.json' -g 'bun.lockb' -g 'AGENTS.md' -g '.nvmrc' -g '.node-version'"completed · exit 0
```
/private/var/folders/w3/c0231jz97cl12bj6q0c8j0fr0000gn/T/greenhorn-baseline-4kqer8
package.json
package-lock.json
README.md
```
/bin/zsh -lc "sed -n '1,240p' README.md && printf '\\n--- package ---\\n' && node --version && npm --version && sed -n '1,220p' package.json && printf '\\n--- git ---\\n' && git status --short"failed · exit 128
```
11.12.1
{
  "name": "greenhorn-fix-loop-demo",
  "version": "1.0.0",
  "private": true
}

--- git ---
fatal: not a git repository (or any of the parent directories): .git
```

/bin/zsh -lc 'npm ci && node verify.js'completed · exit 0

up to date, audited 1 package in 269ms

found 0 vulnerabilities
fix-loop checkpoint passed

Captured 2026-07-18T15:38:47.388Z · Codex exit 0 · raw JSONL-derived transcript