mui/material-ui · error · Error

Could not find '${version}' in "${versions}"

Error message

Could not find '${version}' in "${versions}"

What it means

Thrown when the requested `version` is treated as a dist-tag name but `npm dist-tag ls <pkg>` produced no line beginning with `${version}: `, AND the version string did not look like a concrete semver (it did not start with `^`, `~`, or a digit, so majorVersion stayed null). The check runs inside the reactPackageNames.map loop, so it fires on the first React package whose tag list lacks the entry — typically `react` itself.

Source

Thrown at scripts/useReactVersion.mjs:70

      const tagMapping = versions.split('\n').find((mapping) => {
        return mapping.startsWith(`${version}: `);
      });

      let packageVersion = null;

      if (tagMapping === undefined) {
        // Some specific version is being requested
        if (majorVersion) {
          packageVersion = version;
          if (reactPackageName === 'scheduler') {
            // get the scheduler version from the react-dom's dependencies entry
            const { stdout: reactDOMDependenciesString } = await exec(
              `npm view --json react-dom@${version} dependencies`,
            );
            packageVersion = JSON.parse(reactDOMDependenciesString).scheduler;
          }
        } else {
          throw new Error(`Could not find '${version}' in "${versions}"`);
        }
      } else {
        packageVersion = tagMapping.replace(`${version}: `, '');
      }

      packageJson.resolutions[reactPackageName] = packageVersion;
    }),
  );

  // At this moment all dist tags reference React 18 version, so we don't need
  // to update these dependencies unless an older version is used, or when the
  // next/experimental dist tag reference to a future version of React
  // packageJson.devDependencies['@testing-library/react'] = 'alpha';

  if (majorVersion && additionalVersionsMappings[majorVersion]) {
    devDependenciesPackageNames.forEach((packageName) => {
      if (!additionalVersionsMappings[majorVersion][packageName]) {
        throw new Error(

View on GitHub (pinned to bdc96df2cb)

Solutions

  1. List the real tags with `npm dist-tag ls react` and pass one of those names.
  2. If you want a concrete release instead of a tag, pass a real version (`18.2.0`) or range (`^18`) — those go through the majorVersion branch and skip this throw.
  3. Check registry connectivity and config (`npm config get registry`, `npm ping`) if the tag list comes back empty.

Example fix

// before
$ node scripts/useReactVersion.mjs nex
# Error: Could not find 'nex' in ""

// after
$ node scripts/useReactVersion.mjs next
# (script proceeds to rewrite resolutions and run pnpm install)
Defensive patterns

Strategy: validation

Validate before calling

// Pre-flight: confirm the requested tag exists on npm for every React
// package the script will iterate, so the dist-tag ls loop never throws.
import { exec } from 'node:child_process';
import { promisify } from 'node:util';
const execAsync = promisify(exec);

const reactPackages = ['react', 'react-dom', 'react-is', 'scheduler'];

async function assertTagExists(tag: string) {
  if (/^[~^]/.test(tag) || /^\d/.test(tag)) return; // concrete version/range, not a tag
  for (const pkg of reactPackages) {
    const { stdout } = await execAsync(`npm dist-tag ls ${pkg}`);
    if (!stdout.split('\n').some((line) => line.startsWith(`${tag}: `))) {
      throw new Error(`dist-tag "${tag}" not found for ${pkg}. Available:\n${stdout}`);
    }
  }
}

Type guard

// Narrows a candidate to a known dist-tag name given an npm tag listing.
function isKnownDistTag(
  tag: string,
  listing: string,
): tag is string {
  return listing.split('\n').some((line) => line.startsWith(`${tag}: `));
}

Try / catch

// Distinguish a tag-not-found error from other failures so callers can
// suggest the list of available tags.
try {
  await main(version);
} catch (err) {
  if (err instanceof Error && /Could not find/.test(err.message)) {
    const { stdout } = await execAsync('npm dist-tag ls react');
    throw new Error(`Unknown tag "${version}". Available react dist-tags:\n${stdout}`);
  }
  throw err;
}

Prevention

When it happens

Trigger: Passing a tag name that does not exist on the npm registry for the React packages, e.g. `node scripts/useReactVersion.mjs rc` when there is no `rc` dist-tag. Also fires for arbitrary non-version strings (`latest2`, `foobar`) because they neither match a dist-tag nor parse as a semver.

Common situations: Typo in the tag name (`next` vs `nex`); the React maintainers renamed or removed a dist-tag; querying against a private registry mirror that does not propagate dist-tags; using a tag name that only some sub-packages publish.

Related errors

AI-assisted analysis of mui/material-ui@bdc96df2cb (2026-08-12). Data as JSON: /api/errors/17aba74be7fe5132. Report an issue: GitHub.