Function try_download

emsdk.py:1536–1537

(url)

  url = urljoin(emsdk_packages_url, archive)

  def try_download(url):
    return download_file(url, download_dir, not KEEP_DOWNLOADS, filename_prefix)

  # Special hack for the wasm-binaries we transitioned from `.bzip2` to
  # `.xz`, but we can't tell from the version/url which one to use, so