Even after using libadwaita-1.6.rc (part of GNOME SDK master) to build cambalache flatpak, I receive the following error while opening nautilus:src/gtk/nautilusgtksidebarrow.ui.
Catalogs are updated manually since its a involved process.
The script that creates the catalog from Gir and runtime data is not robust enough for build integration also we need to make sure nothing breaks for example when a new type is added.
It would be great if we can update the catalogs whenever a new release of libadwaita (which changes more rapidly than GTK) and GTK.
Add instructions on how to update the catalogs manually (with a note that things might break). That way one can try updating the catalogs even before official release of libadwaita / GTK, and report any issues, so this delay loop is shortened.