For the current libreoffice rebase (bug 1119709), we want to rebase liblangtag to 0.5.4. This version contains an updated language subtag registry. It also fixes several bugs.
As far as I see this is a bug in gnome-introspection. In this case I can fix it by a simple sed (provided that there is still a time to do a rebuild).
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.