In case people haven't been following the progress of this bug at https://lists.gnu.org/archive/html/bug-gnulib/2020-08/msg00221.html ... It seems that, amongst other issues, we need to upgrade to a newer gnulib commit, and possibly make a few other alterations before a next release.
Somebody also pointed out a "platform-testers" list where one can request portability issues to be tested. J'
