remotion-dev/remotion · error · TypeError

Caching flag must be a boolean.

Error message

Caching flag must be a boolean.

What it means

`Config.setWebpackCaching()` toggles whether the bundler caches its output between runs. It runs a strict `typeof flag !== 'boolean'` check and throws a TypeError on anything else — no coercion.

Source

Thrown at packages/cli/src/config/webpack-caching.ts:7

export const DEFAULT_WEBPACK_CACHE_ENABLED = true;

let webpackCaching = DEFAULT_WEBPACK_CACHE_ENABLED;

export const setWebpackCaching = (flag: boolean) => {
	if (typeof flag !== 'boolean') {
		throw new TypeError('Caching flag must be a boolean.');
	}

	webpackCaching = flag;
};

export const getWebpackCaching = () => {
	return webpackCaching;
};

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Pass a literal boolean: `Config.setWebpackCaching(false)`.
2. For env-driven values, coerce: `Config.setWebpackCaching(process.env.CACHE !== 'false')`.

Example fix

// before
Config.setWebpackCaching(process.env.CACHE);
// after
Config.setWebpackCaching(process.env.CACHE !== 'false');

const raw = process.env.CACHE !== 'false'; // already boolean
if (typeof raw !== 'boolean') {
  throw new Error('CACHE must resolve to a boolean');
}
Config.setWebpackCaching(raw);

const isBoolean = (v: unknown): v is boolean => typeof v === 'boolean';

When it happens

Trigger: Calling `Config.setWebpackCaching('true')`, `setWebpackCaching(1)`, `setWebpackCaching(null)`, or `setWebpackCaching(undefined)`.

Common situations: Reading a flag from `process.env.CACHE` (always a string); deserializing a JSON config value as a string; copy-pasting `'false'` from docs.

Related errors

• Polling must be a number or null, got ${JSON.stringify(
• setImageSequence accepts a Boolean Value
• outputLocation must be a string but got ${typeof newOutputLo
• Studio server port should be a number. Got ${typeof port} ($
• "fps" must be a number, but you passed a value of type ${typ

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/27b61a2cb92f2f69. Report an issue: GitHub.