Package: gir1.2-diodon-1.0 Version: 1.8.0-1 Severity: serious ${gir:Depends} needs "dh --with gir" in debian/rules. The manual dependency on gir1.2-glib-2.0 is no longer necessary when this is fixed.
Something still seems to go wrong afterwards, when trying it did not generate a dependency on libdiodon0.