{
  "approach": "Run 4: intended chain of best responses with seed 4, followed by training against the full chain. Stopped during simulator setup; no candidate model was trained or evaluated.",
  "blocked": "Simulator build failed. Repository archive downloaded and workspace-local Rust stable installed successfully. cargo build --release failed with exit code 101 while linking dependency build scripts: error: linking with `cc` failed: exit status: 1; xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun. Direct clang --version failed with the same error. No simulator executable was produced. Per the setup-failure instruction, stopped before harness validation or training. Null scores mean unmeasured; zero match counts mean no matches ran. Entry is empty because no final model was produced.",
  "current_vs_starter": null,
  "records": {
    "starter": {
      "matches": 0,
      "score": null
    },
    "builtins": {
      "matches": 0,
      "score": null
    },
    "current": {
      "matches": 0,
      "wins": 0,
      "losses": 0,
      "draws": 0,
      "score": null
    },
    "exploiter": {
      "matches": 0,
      "score": null,
      "how": "Not trained: simulator build failed before any matches could run."
    }
  },
  "entry": "",
  "entry_sha256": "",
  "entry_bytes": 0,
  "ops": [],
  "tried": [
    "Fetched and decoded the supplied current entry: 18930 ONNX bytes; SHA256 f3963181497e39089eef5862284d575d5bfc20e6e41b6377b95ee76c436e25b4. This is the supplied baseline, not a new candidate.",
    "Git failed because xcrun was missing; downloaded the public repository archive successfully as a fallback.",
    "Installed Rust stable locally and attempted the repository release build; dependency build scripts failed at the system linker. Completed 0 training iterations and 0 evaluation matches."
  ],
  "next": "Retry run 4 on a worker with a functioning native compiler and linker, preferably the Linux setup described by the current entry. Validate current_vs_starter over 3,000 random-spawn matches before seed-4 best-response training. This blocked result must not replace the current board entry."
}