message: improve prepare_linux_toolchain with missing tools on a fresh machine
diff: @@ -203,6 +203,8 @@ prepare_linux_toolchain() {
  sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
  sudo apt-get update -qq
  sudo apt-get install -qq g++-7 g++-7-multilib swig
  + sudo apt-get install build-essential gradle
  + sudo apt-get install openjdk-11-jdk-headless
  echo "done preparing linux toolchain"
  }
  