What causes "exec is not supported in Cloudflare Workers" in DIYgod/RSSHub?

Ensure the dependency does not reach the exec path under Workers (lazy/guarded).

exec is not supported in Cloudflare Workers

Error message

exec is not supported in Cloudflare Workers

What it means

Inline child_process.exec() inside lib/shims/node-module.ts throws. This mirrors lib/shims/node-child-process.ts because the createRequire builtin map must expose child_process to CJS callers — but exec itself stays unsupported under Workers. Only execSync is stubbed (returns empty Buffer).

Source

Thrown at lib/shims/node-module.ts:84

    },
    runInNewContext: () => {
        throw new Error('vm.runInNewContext is not supported in Workers');
    },
    runInThisContext: () => {
        throw new Error('vm.runInThisContext is not supported in Workers');
    },
    Script: ScriptShim,
    isContext: () => false,
    compileFunction: () => {
        throw new Error('vm.compileFunction is not supported in Workers');
    },
};

// Child process shim (inline to avoid import cycle)
const child_process = {
    execSync: (_command: string): Buffer => Buffer.from(''),
    exec: () => {
        throw new Error('exec is not supported in Cloudflare Workers');
    },
    spawn: () => {
        throw new Error('spawn is not supported in Cloudflare Workers');
    },
    fork: () => {
        throw new Error('fork is not supported in Cloudflare Workers');
    },
    execFile: () => {
        throw new Error('execFile is not supported in Cloudflare Workers');
    },
    execFileSync: () => {
        throw new Error('execFileSync is not supported in Cloudflare Workers');
    },
    spawnSync: () => {
        throw new Error('spawnSync is not supported in Cloudflare Workers');
    },
};

View on GitHub (pinned to bed535e087)

Solutions

Ensure the dependency does not reach the exec path under Workers (lazy/guarded).
Substitute execSync's no-op pattern where a degraded empty result is tolerable.
Run the consuming route on Node.

Example fix

// before
const cp = require('child_process');
cp.exec('git log -1', cb);
// after
const cp = require('child_process');
const out = cp.execSync('git log -1').toString() || 'unknown'; // shim returns ''

Defensive patterns

Strategy: validation

Validate before calling

const isNode = typeof process !== 'undefined' && !!process.versions?.node;
// in CJS-consuming code:
if (isNode) {
  require('child_process').exec(cmd, cb);
} else {
  // Workers: use execSync stub or fetch
}

Type guard

function isWorkersShimError(e: unknown): e is Error {
  return e instanceof Error && /not supported in Cloudflare Workers/.test(e.message);
}

Try / catch

try {
  if (isNode) require('child_process').exec(cmd, cb);
  else return '';
} catch (e) {
  if (isWorkersShimError(e)) return '';
  throw e;
}

Prevention

Audit CJS dependencies reached via createRequire for shell-out calls.
Prefer execSync (shimmed) over exec where a degraded result is acceptable.
Deploy shell-using routes on Node.

When it happens

Trigger: A CJS dependency resolved through module.createRequire(...) that calls child_process.exec() at runtime under Workers.

Common situations: A transitive dependency that shells out; bundler-resolved CJS lib probing for git/shell tools.

Related errors

AI-assisted analysis of DIYgod/RSSHub@bed535e087 (2026-08-12). Data as JSON: /api/errors/8a55f017bdbe7f08. Report an issue: GitHub.