{
  "checker": {
    "details": {
      "argv": [
        "<host-path>",
        "run",
        "-p",
        "difftest",
        "--features",
        "cpp",
        "--",
        "--unit",
        "geom.extent3d"
      ],
      "kind": "cli",
      "needs_browser": false,
      "needs_credentials": false,
      "returncode": 0,
      "scope": "product operation",
      "stderr": "    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s\n     Running `bin/debug/difftest --unit geom.extent3d`",
      "stdout": "PASS geom.extent3d cases=3086 passed=3086 failed=0 deferred=0 max_rel_err=0e0 with_values=3086 no_values=0\n  report: reports/difftest/geom.extent3d.json\ndifftest: 1 unit(s), 1 passed, 0 partial, 0 failed",
      "working": true
    },
    "status": "PASS"
  },
  "deviations": [
    "README 'Building' cargo build -p solidcore: rustc was SIGKILLed (OOM, peak RSS ~910MB, no swap); added 4G swapfile via sudo fallocate/mkswap/swapon, then rebuild succeeded",
    "README prerequisites: rustup, build-essential, pkg-config, cmake and ninja were not present; installed via apt/rustup",
    "harness/cpp/build.sh needs cmake; installed cmake via apt before running it",
    "README 'Difftest': cloned upstream/ (gitignored, lives in workspace; no product source modified)"
  ],
  "main_blocker": null,
  "operation": "Rust-vs-C++ difftest of one unit: cargo run -p difftest --features cpp -- --unit geom.extent3d (PASS, 3086/3086 cases, max_rel_err 0)",
  "operation_scope": "Single documented difftest unit against the upstream C++ reference built in bin/cpp. Not run: --green full sweep, cargo test, cargo clippy/fmt, wasm check, SSI corpus. No MCP/HTTP server exists in this repo (it is a library), so no start/list_tools check applies.",
  "outcome": "working",
  "steps": [
    "Installed rustup (sh.rustup.rs, minimal, no default toolchain); rust-toolchain.toml pinned 1.98.0 auto-installed on first cargo call",
    "apt-get install build-essential pkg-config (cc/linker)",
    "cargo build -p solidcore (SIGKILL with 1.1GB RAM, no swap; fixed by adding 4G /swapfile, then succeeded; also -j1)",
    "git clone https://github.com/NVIDIA-Omniverse/usd-brep upstream && git -C upstream checkout c9c5979",
    "harness/cpp/build.sh (after installing cmake 3.28 + ninja via apt) -> bin/cpp",
    "cargo build -p difftest --features cpp (15 min)",
    "cargo run -p difftest --features cpp -- --unit geom.extent3d -> PASS"
  ],
  "stuck_step": null,
  "suggested_fix": null
}