Function downloadUvBinaryForTarget

packages/python/src/uv.ts:507–569

(
  cacheDir: string
)

 * SHA-256 is verified against {@link UV_BINARY_CHECKSUM}.
 */
export async function downloadUvBinaryForTarget(
  cacheDir: string
): Promise<string> {
  const destDir = join(cacheDir, `uv-${UV_VERSION}-${UV_LINUX_TARGET}`);
  const destBinary = join(destDir, 'uv');

  // Return cached binary if it exists and is executable.
  try {
    await fs.promises.access(destBinary, fs.constants.X_OK);
    debug(`Using cached uv binary at ${destBinary}`);
    return destBinary;
  } catch {
    // Not cached -- continue to download.
  }

  const tarballName = `uv-${UV_LINUX_TARGET}.tar.gz`;
  const url = `https://github.com/astral-sh/uv/releases/download/${UV_VERSION}/${tarballName}`;

  debug(`Downloading uv ${UV_VERSION} from ${url}`);
  console.log(
    `Downloading uv ${UV_VERSION} (linux x86_64) for runtime dependency installation...`
  );

  await fs.promises.mkdir(destDir, { recursive: true });
  const tarballPath = join(destDir, tarballName);

  await downloadUvTarball(url, tarballPath);

  const actualHash = await sha256File(tarballPath);
  if (actualHash !== UV_BINARY_CHECKSUM) {
    await fs.promises.unlink(tarballPath).catch(() => {});
    throw new NowBuildError({
      code: 'RUNTIME_DEPENDENCY_INSTALLATION_FAILED',
      message:
        `checksum mismatch for ${tarballName}: ` +
        `expected ${UV_BINARY_CHECKSUM}, got ${actualHash}`,
    });
  }

  // Archive contains `uv-{target}/uv` (and uvx).
  try {
    await execa('tar', [
      'xzf',
      tarballPath,
      '--strip-components=1',
      '-C',
      destDir,
    ]);
  } catch (err) {
    throw new NowBuildError({
      code: 'RUNTIME_DEPENDENCY_INSTALLATION_FAILED',
      message: `could not extract ${tarballName}: ${
        err instanceof Error ? err.message : String(err)
      }`,
    });
  }

  await fs.promises.chmod(destBinary, 0o755);