found 832077 emacs/46.1 thanks The message
(emacs:6144): Gtk-WARNING **: GtkWindow 0xc50270 is drawn without a current allocation. This should not happen.
is printed to xterm from where emacs was started. Printing happens when the emacs window gets the focus due to a left-button mouse click.
For me, it's not a huge trouble, but still, annoying.