[tz] latest zic mishandles Africa/Cairo past 2038?

When I run the command "make check_public" in the tz distribution, several warnings are generated. I'd like to fix things so that it builds cleanly. Let's start with the first warning: "africa", line 190: warning: no POSIX environment variable for zone Africa/Cairo As I understand it, this warning is saying that zic can't deduce a POSIX-style TZ setting for Africa/Cairo time stamps predicted past 2038. But if you look at the data, there's a straightforward POSIX-style setting for that, namely TZ='EET-2'. My guess is that zic is confused because the most-recent Rule is for 2010. Is my guess correct? Is this a bug in zic.c, which can be fixed?