Eli Zaretskii writes:
>> It's said to be the only _binary_ incompatibility.
> Where did you see that? I don't think I have, but maybe I missed
I may be reading too much into the release blurb, but it says "binary
incompatibility notice" and then lists only the two items discussed, of
which the second cannot apply to C programs (so it must be the C++ ABI
change) — that leaves the first item for the C ABI change only.