More on preview4 warnings:
I'm posting here because I can't see the root message.

Preview4 builds on hp/compaq tru64 (osf1) 5.1.
I get many many warnings.
Most are signed/unsigned pointer type errors, like this one:
cc -ieee -g -oldc -std  -I. -I. -c array.c
cc: Warning: array.c, line 1820: In this statement, the referenced
type of the p
ointer value "&v" is "unsigned long", which is not compatible with
"long" becaus
e they differ by signed/unsigned attribute. (ptrmismatch1)
        if (st_delete(RHASH(hash)->tbl, &v, 0)) {
----------------------------------------^
There are 95 warnings of this type (ptrmismatch1).

There are 24 Warning: Unresolved: linkage warnings, which I guess
should just be ignored.

There are 6 more warnings left:
1)
cc -ieee -g -oldc -std  -I. -I. -c file.c
cc: Warning: file.c, line 1048: Non-void function "rb_file_s_lchmod"
does not co
ntain a return statement. (missingreturn)
static VALUE
^
2)
cc -ieee -g -oldc -std  -I. -I. -c process.c
cc: Warning: process.c, line 1478: Non-void function "p_sys_issetugid"
does not
contain a return statement. (missingreturn)
static VALUE
^
3)
cc -ieee -g -oldc -std -I. -I/u13/home/doug/ruby/ruby-1.8.0
-I/u13/home/doug/rub
y/ruby-1.8.0 -I/u13/home/doug/ruby/ruby-1.8.0/ext/curses
-DHAVE_CURSES_H -DHAVE_
ISENDWIN -DHAVE_UNGETCH -DHAVE_BEEP -DHAVE_GETNSTR -DHAVE_WGETNSTR
-DHAVE_DOUPDA
TE -DHAVE_FLASH -DHAVE_DELETELN -DHAVE_WDELETELN -DHAVE_KEYPAD
-DHAVE_KEYNAME -D
HAVE_INIT_COLOR  -c curses.c
cc: Warning: curses.c, line 434: In this statement, "keyname(...)" of
type "int"
, is being converted to "pointer to const char". (cvtdiftypes)
  name = keyname(NUM2INT(c));
--^
4)
cc -Dsocklen_t=int -DHAVE_GETADDRINFO -DHAVE_SOCKADDR_STORAGE -DINET6
-ieee -g -
oldc -std -DENABLE_IPV6 -I. -I/u13/home/doug/ruby/ruby-1.8.0
-I/u13/home/doug/ru
by/ruby-1.8.0 -I/u13/home/doug/ruby/ruby-1.8.0/ext/socket
-DHAVE_NETINET_TCP_H -
DHAVE_NETINET_UDP_H -DHAVE_ST_MSG_ACCRIGHTS -DHAVE_GETADDRINFO
-DHAVE_GETNAMEINF
O -DHAVE_SYS_UN_H -DHAVE_SYS_UIO_H -DHAVE_SOCKET -DHAVE_GETHOSTNAME 
-c socket.c
cc: Warning: socket.c, line 1127: The scalar variable "size" is
fetched but not
initialized.  And there may be other such fetches of this variable
that have not
 been reported in this compilation. (uninit1)
            memcpy((char*)&sin6.sin6_addr, *pch, size);
-------------------------------------------------^
5)
cc -ieee -g -oldc -std -I. -I/u13/home/doug/ruby/ruby-1.8.0
-I/u13/home/doug/rub
y/ruby-1.8.0 -I/u13/home/doug/ruby/ruby-1.8.0/ext/syck -DHAVE_ST_H  -c
emitter.c
cc: Warning: emitter.c, line 174: In this statement, this argument to
sprintf co
ntains a bad conversion specification "%Y" that will cause
unpredictable behavio
r. (badconvspec)
            sprintf( header, "--- %YAML:%d.%d ", SYCK_YAML_MAJOR,
SYCK_YAML_MINO
R );
-----------------------------^
6)
cc -ieee -g -oldc -std -I. -I/u13/home/doug/ruby/ruby-1.8.0
-I/u13/home/doug/rub
y/ruby-1.8.0 -I/u13/home/doug/ruby/ruby-1.8.0/ext/tcltklib
-DHAVE_TCL_H -DHAVE_T
K_H  -c stubs.c
cc: Warning: stubs.c, line 94: Source file does not contain any
declarations. (e
mptyfile)
#endif
------^


Of these warnings, only number 4(uninitialized) and 5(bad conversion)
scare me.

Should I investigate these, or just ignore them?

Doug