Upgrade Qt 5.12.3

snap/snapcraft.yaml

@@ -51,10 +51,17 @@ parts:
   prepare:
     plugin: nil
     prepare: |
+      # SDL upgrade
       echo "deb http://ppa.launchpad.net/litenstein/sdl2-xenial/ubuntu xenial main" | tee /etc/apt/sources.list.d/litenstein-ubuntu-sdl2-xenial-xenial.list
       apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1E0A4B32AA748B9D11C4528301A509285F2EA337
+
+      # Qt upgrade (5.12.3)
+      echo "deb http://ppa.launchpad.net/beineri/opt-qt-5.12.3-xenial/ubuntu xenial main" | tee /etc/apt/sources.list.d/beineri-ubuntu-opt-qt-5_11_1-xenial-bionic.list
+      apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C65D51784EDC19A871DBDBB710C56D0DE9977759
+
+      # Install updated packages
       apt-get update
-      apt-get install -y libsdl2-2.0-0
+      apt-get install -y libsdl2-2.0-0 qt512-meta-full
     prime: [-*]
   launcher:
     plugin: cmake