vercel/turborepo · error

New workspace is missing a package.json file

Error message

New workspace is missing a package.json file

What it means

The turbo-gen copy generator requires every new workspace to have a package.json. After copying an external example, it checks that the destination package.json exists. It throws this Error when the file is absent, then logs it and deletes the copied directory as a rollback.

Solutions

  1. Open the copy source and confirm which directory holds the package.json
  2. Adjust the copy URL or example path so it targets that directory
  3. If you own the source, add a valid package.json to the copied directory

Example fix

# before: path without a package.json
npm exec turbo gen -- --copy https://github.com/org/repo --example-path docs
# after: path that contains the package
npm exec turbo gen -- --copy https://github.com/org/repo --example-path apps/demo
Defensive patterns

Strategy: validation

Validate before calling

import fs from "node:fs";

// confirm the copy target contains a package.json before running turbo gen
if (!fs.existsSync(path.join(sourceDir, "package.json"))) {
  throw new Error(`${sourceDir} has no package.json; pick a package directory`);
}

Type guard

function isPackageDirectory(dir: string): boolean {
  return fs.existsSync(`${dir}/package.json`);
}

Prevention

When it happens

Trigger: The copy source contains no package.json at its root. This happens when the example path points at a subfolder without one, at an empty repository, or at a repo whose layout changed. fs.existsSync(newPackageJsonPath) is false, so the else branch throws.

Common situations: examplePath points to a docs folder or asset directory instead of a package. The upstream example restructured and the old path no longer holds a package. The repository name in the copy URL is misspelled, so an empty tree is copied.

Related errors

AI-assisted analysis of vercel/turborepo@f9245100cf (2026-08-17). Data as JSON: /api/errors/749a694d9efdde8a. Report an issue: GitHub.

Appendix: source

Thrown at packages/turbo-gen/src/generators/copy.ts:47

    );
    await createProject({
      appPath: location.absolute,
      example: opts.copy.source,
      examplePath: opts.examplePath
    });

    try {
      if (fs.existsSync(newPackageJsonPath)) {
        const packageJson = (await fs.readJSON(
          newPackageJsonPath
        )) as PackageJson;
        if (packageJson.workspaces) {
          throw new Error(
            "New workspace root detected - unexpected 'workspaces' field in package.json"
          );
        }
      } else {
        throw new Error("New workspace is missing a package.json file");
      }

      if (fs.existsSync(path.join(location.absolute, "pnpm-workspace.yaml"))) {
        throw new Error(
          "New workspace root detected - unexpected pnpm-workspace.yaml"
        );
      }
    } catch (err) {
      let message = "UNKNOWN_ERROR";
      if (err instanceof Error) {
        message = err.message;
      }
      logger.error(message);

      // rollback changes
      await fs.rm(location.absolute, { recursive: true, force: true });
      return;
    }

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