I wrote:
> One angle that ought to be considered is that some of this stuff may
> be flat-out bugs in 2.13.0. I see at
> https://gitlab.gnome.org/GNOME/libxml2/-/releases
> that both 2.13.1 and 2.13.2 contain fixes for "regressions" in 2.13.0.
> I'm disinclined to spend much effort on working around dot-zero bugs.
Meh ... 2.13.1, at least, changes nothing here.
regards, tom lane