message: Check whether build tools are installed
  Print warning/error and exit early if cmake, ninja/make cannot be found.
diff: @@ -285,14 +285,31 @@ function build_android {
  }
  function validate_build_command {
  + set +e
  + # Make sure CMake is installed
  + cmake_binary=`which cmake`
  + if [ ! "$cmake_binary" ]; then
  + echo "Error: could not find cmake, exiting"
  + exit 1
  + fi
  +
  # Make sure Ninja is installed
  if [ "$BUILD_COMMAND" == "ninja" ]; then
  - ninja_binary=`which ninja`
  + ninja_binary=`which ninja2`
  if [ ! "$ninja_binary" ]; then
  echo "Warning: could not find ninja, using make instead"
  BUILD_COMMAND="make"
  fi
  fi
  + # Make sure Make is installed
  + if [ "$BUILD_COMMAND" == "make" ]; then
  + make_binary=`which make`
  + if [ ! "$make_binary" ]; then
  + echo "Error: could not find make, exiting"
  + exit 1
  + fi
  + fi
  + set -e
  }
  # Beginning of the script
  