Critical error messages when parsing themes
We (Xfce devs) are facing a flooding of critical error messages when parsing themes with gtk_css_provider_to_string. At some point it was caused by few themes (e.g. Greybird), but now it's reproducible even with Adwaita (gtk 3.24.5 here).
I'd love to avoid theme serialization, but I'm not aware of any other way to figure out if the current theme declares a css class or not. We are not the only ones using this approach (spoiler: Nemo also pollutes .xsession-errors): https://github.com/linuxmint/nemo/blob/e7016c87b29b9e74f04a55f08ef3610c01e59da0/src/nemo-application.c#L177
And Eclipse is also affected: https://bugs.eclipse.org/bugs/show_bug.cgi?id=530781
That being the case, is there any workaround or this should be fixed in glib?
Downstream bug: https://bugzilla.xfce.org/show_bug.cgi?id=13928