Here is my feedback with a gnome-shell session. I'm using gnome3-staging ppa since a couple months now, and have not met issue. The journalctl indeed log some warnings, but have no sad viewable effect:
org.gnome.Shell.desktop[1910]: (gnome-shell:1910): Gtk-WARNING **: Theme parsing error: gtk-widgets-borders.css:31:18: The :insensitive pseudo- class is deprecated. Use :disabled instead. org.gnome.Shell.desktop[1910]: (gnome-shell:1910): Gtk-WARNING **: Theme parsing error: gtk-widgets-borders.css:226:33: The :focused pseudo-class is deprecated. Use :focus instead. org.gnome.Shell.desktop[1910]: (gnome-shell:1910): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:16:33: The style property GtkMenu :horizontal-padding is deprecated and shouldn't be used anymore. It will be removed in a future version ..... The style property GtkMenu:vertical-padding is deprecated and shouldn't be used anymore. It will be removed in a future version .... The style property GtkMenuItem:arrow-scaling is deprecated and shouldn't be used anymore. It will be removed in a future version ...The style property GtkNotebook:tab-overlap is deprecated and shouldn't be used anymore. It will be removed in a future version ... The style property GtkWidget:separator-width is deprecated and shouldn't be used anymore. It will be removed in a future version ....The style property GtkWidget:separator-height is deprecated and shouldn't be used anymore. It will be removed in a future version ...The style property GtkWidget:wide-separators is deprecated and shouldn't be used anymore. It will be removed in a future version ....The style property GtkWidget:link-color is deprecated and shouldn't be used anymore. It will be removed in a future version ...The style property GtkWidget:visited-link-color is deprecated and shouldn't be used anymore. It will be removed in a future version .... unity.css:109:15: The 'icon-shadow' property has been renamed to '-gtk-icon-shadow' .... gedit.css:65:67: The :prelight pseudo-class is deprecated. Use :hover instead. ...... That is: lot of warning spams but nothing else. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to gtk+3.0 in Ubuntu. https://bugs.launchpad.net/bugs/1576576 Title: Update to 3.20 needs work and coordination Status in Ubuntu GNOME: New Status in gtk+3.0 package in Ubuntu: Confirmed Bug description: The current upstream stable/Debian version is 3.20 but that includes quite some changes in the css handling which means we are going to need to update/fix the unity themes and make sure you main application look fine before landing. The transition needs to be prepared in a staging ppa before being considered, help is welcome since it's likely the desktop team is not going to have lot of cycles to work on that. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-gnome/+bug/1576576/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp

