ruvnet/RuView · error · RangeError

maxOutputBytes must be a positive safe integer

Error message

maxOutputBytes must be a positive safe integer

What it means

runProcess() caps captured child output with maxOutputBytes and requires a positive safe integer (>= 1, integral, <= Number.MAX_SAFE_INTEGER). Values of 0, negatives, fractions, NaN, Infinity, or numbers beyond the safe-integer range throw this RangeError before the child spawns.

Source

Thrown at harness/homecore/src/process-runner.js:106

export function runProcess(command, args = [], {
  cwd,
  input = '',
  timeoutMs = 120_000,
  signal,
  maxOutputBytes = 1_048_576,
  env = process.env,
  envAllowlist = DEFAULT_ENV_ALLOWLIST,
} = {}) {
  if (!command || typeof command !== 'string') throw new TypeError('command must be a non-empty string');
  if (!Array.isArray(args) || !args.every((arg) => typeof arg === 'string')) {
    throw new TypeError('args must be an array of strings');
  }
  if (!Number.isSafeInteger(timeoutMs) || timeoutMs < 1_000 || timeoutMs > 1_800_000) {
    throw new RangeError('timeoutMs must be a safe integer between 1000 and 1800000');
  }
  if (!Number.isSafeInteger(maxOutputBytes) || maxOutputBytes < 1) {
    throw new RangeError('maxOutputBytes must be a positive safe integer');
  }
  const childEnv = scrubEnvironment(env, envAllowlist);

  return new Promise((resolve, reject) => {
    const child = spawn(command, args, {
      cwd,
      env: childEnv,
      detached: process.platform !== 'win32',
      shell: false,
      windowsHide: true,
      stdio: ['pipe', 'pipe', 'pipe'],
    });
    const stdout = [];
    const stderr = [];
    let outputBytes = 0;
    let overflow = false;
    let timedOut = false;
    let settled = false;

View on GitHub (pinned to 4685618388)

Solutions

1. Pass an explicit positive integer cap such as the default 1_048_576 or 2_097_152
2. Validate computed values with Number.isSafeInteger(v) && v >= 1 before the call
3. Do not use 0 or Infinity to mean unlimited; choose the largest acceptable cap explicitly

Example fix

// before
await runProcess('cargo', ['test'], { maxOutputBytes: 0 }); // meant unlimited

// after
await runProcess('cargo', ['test'], { maxOutputBytes: 2_097_152 });

function normalizeMaxOutputBytes(value, fallback = 1_048_576) {
  return Number.isSafeInteger(value) && value >= 1 ? value : fallback;
}
// use: runProcess(cmd, args, { maxOutputBytes: normalizeMaxOutputBytes(cfg.limit) })

/** @param {unknown} v @returns {v is number} */
function isValidMaxOutputBytes(v) {
  return Number.isSafeInteger(v) && v >= 1;
}

try {
  await runProcess(cmd, args, { maxOutputBytes });
} catch (error) {
  if (error instanceof RangeError && error.message.includes('maxOutputBytes')) {
    throw new Error(`maxOutputBytes=${maxOutputBytes} must be a positive safe integer`);
  }
  throw error;
}

When it happens

Trigger: {maxOutputBytes: 0} intending 'unlimited', {maxOutputBytes: NaN} from arithmetic on undefined, {maxOutputBytes: 1e21} beyond the safe-integer range, or negative values from subtraction.

Common situations: Using 0 to disable the cap (unsupported), computing the cap from float math or user input, Infinity defaults leaking into options via object spread.

Related errors

• timeoutMs must be a safe integer between 1000 and 1800000
• command must be a non-empty string
• args must be an array of strings
• Unsupported verification profile: ${profile}
• unsupported guidance topic: ${topic}

AI-assisted analysis of ruvnet/RuView@4685618388 (2026-08-16). Data as JSON: /api/errors/537cdc3d58d47ce4. Report an issue: GitHub.