raspi-config now checks for mesa driver before allowing GL driver to be enabled.

raspi-config

@@ -1003,6 +1003,10 @@ do_gldriver() {
     whiptail --msgbox "Driver and kernel not present on your system. Please update" 20 60 2
     return 1
   fi
+  if [ $(dpkg -l libgl1-mesa-dri | tail -n 1 | cut -d ' ' -f 1) != "ii" ]; then
+    whiptail --msgbox "libgl1-mesa-dri not found - please install" 20 60 2
+    return 1
+  fi
   if [ ! -e /usr/bin/xcompmgr ]; then
     whiptail --msgbox "xcompmgr not found - please install" 20 60 2
     return 1