message: github workflow ubuntu: update apt first
diff: @@ -20,6 +20,7 @@ jobs:
  run: |
  set -ex
  cat /etc/apt/sources.list
  + sudo apt -q update
  sudo apt install -y "g++-9" \
  libfreetype6-dev libglew-dev libglfw3-dev libglm-dev \
  libfontconfig1-dev libharfbuzz-dev
  