🚀 go-pugleaf

 >I don't know about vanilla 4.2, but I didn't have much problems
 >making the IDA Kit [which is based on 5.59] run under SunOS 3.x -- in
 >addition to removing the third parameter of the openlog() call in main.c
 >to, all I had to do was to remove the unsetenv() call in main.c and to
 >change the way the local time zone was gathered in arpadate.c to use
 >localtime() instead of timezone().

You will probably have to do all three to make it run under 4.2BSD.

The first change is a change between 4.2's "openlog" and 4.3's "openlog"
(since SunOS 4.0 uses 4.3's "openlog", it shouldn't be necessary under
SunOS 4.0).

The second change (which I presume you meant the other way around -
change to use "timezone()" instead of "localtime()") is a change between
V7's/4.2's/4.3's time zone handling code and 4.3-tahoe's time zone
handling code (SunOS 4.0 uses the Arthur Olson time zone code, with
"tm_zone" added, just as 4.3-tahoe does, so this change shouldn't be
necessary under SunOS 4.0). 

Note that some parts of 4.3BSD were in SunOS 3.2 and later, so you may
run into some more changes that have to be made to make it work under
vanilla 4.2BSD.