Illegal reflective access by processing.app.linux.GTKLookAndFeelFixer

[mMerlin]

Environment:

• 4.18.16-300.fc29.x86_64
• Arduino 1.8.5

This is a fresh load from scratch of Fedora 29 from Fedora-Workstation-Live-x86_64-29-1.2.iso.

sudo dnf upgrade
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak install flathub cc.arduino.arduinoide
sudo usermod -a -G dialout «…»

reboot

$ flatpak run cc.arduino.arduinoide 
Picked up JAVA_TOOL_OPTIONS: 
Gtk-Message: Failed to load module "pk-gtk-module"
Gtk-Message: Failed to load module "canberra-gtk-module"
Gtk-Message: Failed to load module "pk-gtk-module"
Gtk-Message: Failed to load module "canberra-gtk-module"
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by processing.app.linux.GTKLookAndFeelFixer (file:/app/Arduino/lib/arduino-core.jar) to field com.sun.java.swing.plaf.gtk.GTKLookAndFeel.styleFactory
WARNING: Please consider reporting this to the maintainers of processing.app.linux.GTKLookAndFeelFixer
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

The app still runs correctly, as far as I can tell. Currently only a warning, but the messages say it will be denied in a future release. Of flatpak I assume.

[rombert]

Currently only a warning, but the messages say it will be denied in a future release. Of flatpak I assume.

Actually that's a future release of Java.