babel/babel · error · Error

Cannot update ${dataURL}

Error message

Cannot update ${dataURL}

What it means

Error "Cannot update ${dataURL}" thrown in babel/babel.

Source

Thrown at packages/babel-compat-data/scripts/build-data.mjs:32

}

function buildPluginFeatures() {
  // We ignore 'overlapping' here, because it's already generated by
  // built-bugfixes-targets.js which has a complete view over all the
  // plugins that we have data for.
  let { data: newData } = generateData(environments, pluginFeatures);
  // add export-namespace-from from @mdn/browser-compat-data
  newData["transform-export-namespace-from"] = generateModuleSupport(
    compatData.statements.export.namespace,
    true
  );

  // Add proposal-* aliases for backward compatibility.
  newData = maybeDefineLegacyPluginAliases(newData);
  const dataURL = new URL(`../data/plugins.json`, import.meta.url);

  if (!writeFile(newData, dataURL, "plugin")) {
    throw new Error(`Cannot update ${dataURL}`);
  }
}

buildPluginFeatures();

View on GitHub (pinned to 06b6eae39d)

Solutions

1. Check write permissions on packages/babel-compat-data/data/plugins.json and ensure the file is not locked or read-only.
2. Verify the generated data is valid; writeFile returns false when it cannot serialize or write the output.

When it happens

Trigger: Thrown at packages/babel-compat-data/scripts/build-data.mjs:32 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of babel/babel@06b6eae39d (2026-08-03). Data as JSON: /data/errors/c0d034964c102f3b.json. Report an issue: GitHub.