Yo, today compiled (successfully) ruby-1.8.0-preview 4 on NetBSD 1.6U
(i.e. NetBSD -current from like 17 days ago) and it only had (without
-Wall!) the following warnings:

libruby-static.a(process.o): In function `p_sys_setruid':
/usr/home/phaeton/tmp/ruby/ruby-1.8.0/process.c:1200: warning: this program
uses setruid(), which is deprecated.
libruby-static.a(process.o): In function `p_sys_setrgid':
/usr/home/phaeton/tmp/ruby/ruby-1.8.0/process.c:1435: warning: this program
uses setrgid(), which is deprecated.
./libruby-static.a(process.o): In function `p_sys_setruid':
/usr/home/phaeton/tmp/ruby/ruby-1.8.0/process.c:1200: warning: this program
uses setruid(), which is deprecated.
./libruby-static.a(process.o): In function `p_sys_setrgid':
/usr/home/phaeton/tmp/ruby/ruby-1.8.0/process.c:1435: warning: this program
uses setrgid(), which is deprecated.

(that's "err" from make > out 2> err)

(*giggle* I was curious and checked their manpage: quote:
HISTORY
     The setruid() and setrgid() syscalls appeared in 4.2BSD and were dropped
     in 4.4BSD.
4.4BSD ? that's been some time :)

make test succeeds.

With -Wall err is 156 lines, if you want to, can send that email privately.
Most warnings are things like
eval.c:2233: warning: variable `node_save' might be clobbered by `longjmp' or `vfork', 
some suggestions of paren use, and

dln.c: In function `dln_strerror':
dln.c:1187: warning: implicit declaration of function `dlerror' 
dln.c: In function `dln_load':
dln.c:1323: warning: implicit declaration of function `dlopen'
dln.c:1328: warning: implicit declaration of function `dlsym'
dln.c:1331: warning: implicit declaration of function `dlclose'

...some unused variables, uninitialized warnings stuff defined and not used
and that's it.

...or I can just test preview5 again as I guess most of the warnings have
been fixed already.

regards,

-martin
--
Programming Ruby: When you're too wasted to even watch TV.