Flutter apps fail to run on Wayland

[Saviq]

On a Wayland desktop, Flutter apps fail to run.

Steps:

$ snap install flutter-gallery
$ snap disconnect flutter-gallery:x11
$ snap connect flutter-gallery:wayland
$ snap run flutter-gallery

(flutter_gallery:356312): Gtk-WARNING **: 15:03:16.606: cannot open display: :0

It seems to still look at the X11-specific DISPLAY var:

$ env -u DISPLAY snap run flutter-gallery

(flutter_gallery:356391): Gtk-WARNING **: 15:03:41.364: cannot open display: 

flokk-contacts seems to go further, but fails to render:

$ flokk-contacts

(flokk-contacts:2925060): Gtk-WARNING **: 16:45:42.810: Theme parsing error: gtk.css:1555:23: 'font-feature-settings' is not a valid property name

(flokk-contacts:2925060): Gtk-WARNING **: 16:45:42.814: Theme parsing error: gtk.css:3591:25: 'font-feature-settings' is not a valid property name

(flokk-contacts:2925060): Gtk-WARNING **: 16:45:42.815: Theme parsing error: gtk.css:4053:23: 'font-feature-settings' is not a valid property name

(flokk-contacts:2925060): Gdk-WARNING **: 16:45:43.157: ../../../../../gdk/x11/gdkwindow-x11.c:5579 drawable is not a native X11 window

** (flokk-contacts:2925060): WARNING **: 16:45:43.419: Failed to start Flutter engine: Failed to create EGL surface: Bad Native Window

[wmww]

It seems to still look at the X11-specific DISPLAY var:

FYI GTK often shows cannot open display: :0 even on Wayland and even when DISPLAY is not involved. The error can even mean ":0 exists but GDK_BACKEND=wayland forced me not to use it"

[MarcusTomlinson]

Will be fixed by: flutter/gallery#455

[Saviq]

I can confirm flutter/gallery#455 fixes it there. Filed gskinnerTeam/flokk#42, as it likely just needs a rebuild with new Flutter engine supporting Wayland.