Clean up fetch_url

  popd >&4

}

if type curl &>/dev/null; then

fetch_url() { curl "$@" ;}

elif type wget &>/dev/null; then

fetch_url() { wget -O- "$@" ;}

fetch_url() {

  if type curl 2>/dev/null; then

    curl "$@"

  elif type wget 2>/dev/null; then

    wget -O- "$@"

  else

fetch_url() { echo "curl or wget is required" >&2; exit 1 ;}

    echo "error: please install \`curl\` or \`wget\` and try again" >&2

    exit 1

  fi

}

fetch_tarball() {

  local package_name="$1"