Install to SunOS oobi 5.10 Generic i86pc i386 i86pc. please help.

[Jean Mao]

Hello:

   I downloaded emacs-21.4 and is trying to build and install to a
SunOS oobi 5.10 Generic i86pc i386 i86pc

I got:
oobi:spg [195] cc -c  -Demacs -DHAVE_CONFIG_H -DUSE_LUCID  -I. 
-I/home/spg/jean/emacs-21.4/src    -I/usr/openwin/include  
-I/usr/dt/include -g -O src/strftime.c
"src/strftime.c", line 608: improper cast of void expression
"src/strftime.c", line 608: improper cast of void expression
"src/strftime.c", line 641: improper cast of void expression
"src/strftime.c", line 641: improper cast of void expression
"src/strftime.c", line 726: improper cast of void expression
"src/strftime.c", line 726: improper cast of void expression
"src/strftime.c", line 811: improper cast of void expression
"src/strftime.c", line 811: improper cast of void expression
"src/strftime.c", line 847: improper cast of void expression
"src/strftime.c", line 847: improper cast of void expression
"src/strftime.c", line 992: improper cast of void expression
"src/strftime.c", line 992: improper cast of void expression
"src/strftime.c", line 1044: improper cast of void expression
"src/strftime.c", line 1044: improper cast of void expression
;;;;;;;;

What might be wrong? Thank you in advance for your help.

Jean