Rubén Justo <rjusto@xxxxxxxxx> writes: > Here, perhaps you want to do: > > err(s, _("Only one letter is expected, got '%s'"), s->answer.buf); True. The end-user errors are reported with err() in the surrounding code. I however was hoping that this can be based on v2.44.0, which predates 9d225b02 (add-patch: do not show UI messages on stderr, 2024-04-29), which makes the testing of it a bit cumbersome.