Andres Freund <andres@anarazel.de> writes:
> It seems Mark started a new buildfarm animal on s390x. It shows a pretty
> odd failure on 9.3 and 9.4, but *not* on newer animals:
No, lumpsucker is showing the same failure on 9.5 as well. I suspect
that the reason 9.6 and up are OK is that 9.6 is where we introduced
the abbreviated-sort-key machinery. IOW, the problem exists in the
old-style UUID sort comparator but not the new one. Which is pretty
darn odd, because the old-style comparator is just memcmp(). How
could that be broken without causing lots more issues?
regards, tom lane