vercel/turborepo · error · ConvertError

package_manager-could_not_be_found

package_manager-could_not_be_found

Error message

${convertTo.name} is not installed, or could not be located

What it means

convertProject() requires the target package manager's version to be resolvable (convertTo.version). A missing version means the manager binary could not be located or interrogated, so it throws ConvertError type package_manager-could_not_be_found instead of shelling out to a command that does not exist.

Source

Thrown at packages/turbo-workspaces/src/convert.ts:47

}: {
  project: Project;
  convertTo: RequestedPackageManagerDetails;
  logger: Logger;
  options?: Options;
}) {
  logger.header(
    `Converting project from ${project.packageManager} to ${convertTo.name}.`
  );

  if (!options?.ignoreUnchangedPackageManager) {
    if (project.packageManager === convertTo.name) {
      throw new ConvertError("You are already using this package manager", {
        type: "package_manager-already_in_use"
      });
    }

    if (!convertTo.version) {
      throw new ConvertError(
        `${convertTo.name} is not installed, or could not be located`,
        {
          type: "package_manager-could_not_be_found"
        }
      );
    }
  }

  // this cast is safe since we've just verified that the version exists above
  const to = convertTo as AvailablePackageManagerDetails;

  // remove old workspace data
  if (!options?.ignoreUnchangedPackageManager) {
    await MANAGERS[project.packageManager].remove({
      project,
      to,
      logger,
      options

View on GitHub (pinned to 9f94a7d215)

Solutions

1. Install the target manager (e.g. npm i -g pnpm, or bun's official installer) and confirm `<manager> --version` works in the same shell
2. Re-run the conversion after ensuring the binary is on PATH
3. If it is installed but undetected, fix PATH ordering or invoke the conversion from a shell where the manager resolves

Example fix

# before: bun not installed
npx @turbo/workspaces convert --to bun # 'bun is not installed...'

# after
curl -fsSL https://bun.sh/install | bash
bun --version # sanity check, then re-run

import { execSync } from "node:child_process";

function managerVersion(command: string): string | undefined {
  try {
    return execSync(`${command} --version`, { stdio: "pipe" }).toString().trim();
  } catch {
    return undefined;
  }
}

if (!managerVersion(convertTo.name)) {
  throw new Error(`Install ${convertTo.name} before converting`);
}

function isManagerMissingError(e: unknown): boolean {
  return e instanceof ConvertError && e.type === "package_manager-could_not_be_found";
}

try {
  await convertProject({ project, convertTo, logger });
} catch (e) {
  if (e instanceof ConvertError && e.type === "package_manager-could_not_be_found") {
    // prompt: `pnpm not found — install it?` then retry after install
  } else throw e;
}

When it happens

Trigger: Targeting npm/pnpm/yarn/bun/nub/aube when the binary is not installed or not on PATH, so the version lookup that built the RequestedPackageManagerDetails produced no version. Bypassed only by options.ignoreUnchangedPackageManager.

Common situations: Converting to bun on a machine that never installed bun; CI images lacking the target manager; nvm/volta shims inactive in the current shell; Windows PATH missing the .cmd shim.

Related errors

• package_manager-already_in_use
• package_manager-unsupported_version
• bun-workspace_glob_error
• Unable to update README.md
• invalid_directory

AI-assisted analysis of vercel/turborepo@9f94a7d215 (2026-08-16). Data as JSON: /api/errors/3a180d03a1185f56. Report an issue: GitHub.