https://bugzilla.redhat.com/show_bug.cgi?id=1348912
--- Comment #12 from Alexander Kurtakov akurtako@redhat.com --- So SWT uses gtk_widget_override_font which has been deprecated for some time in gtk and its behavior changed. There is wip patch available at https://git.eclipse.org/r/#/c/75861 that uses the CSS machinery as GTK devs have been advertizing but is not fully ready yet.