getting the following error on a Solaris-10 (Sparc) machine (during make)

-----------------------
gcc -DHAVE_CONFIG_H -I. -I. -I.. -I../include -I/usr/include/gtk-2.0
-I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/pango-1.0
-I/usr/openwin/include -I/usr/sfw/include -I/usr/sfw/include/freetype2
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/local/include/xfce4
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -g -O2 -MT
libxfce4mixer_la-vc_sun.lo -MD -MP -MF .deps/libxfce4mixer_la-vc_sun.Tpo -c
vc_sun.c  -fPIC -DPIC -o .libs/libxfce4mixer_la-vc_sun.o
vc_sun.c:85: warning: static declaration of 'vc_reinit_device' follows
non-static declaration
vc_sun.c:72: warning: previous implicit declaration of 'vc_reinit_device' was here
vc_sun.c:94: error: conflicting types for 'vc_set_device'
vc_sun.c:71: error: previous implicit declaration of 'vc_set_device' was here
make[2]: *** [libxfce4mixer_la-vc_sun.lo] Error 1
make[2]: Leaving directory `/root/xfce-build/xfce4-mixer/lib'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/root/xfce-build/xfce4-mixer'
make: *** [all] Error 2 
---------------------------------




Reproducible: Always
Steps to Reproduce:
1. ./configure
2. make
3. 

Actual Results:  
# make
make  all-recursive
make[1]: Entering directory `/root/xfce-build/xfce4-mixer'
Making all in lib
make[2]: Entering directory `/root/xfce-build/xfce4-mixer/lib'
if /bin/bash ../libtool --mode=compile --tag=CC gcc -DHAVE_CONFIG_H -I. -I. -I..
-I../include   -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include
-I/usr/include/atk-1.0 -I/usr/include/pango-1.0 -I/usr/openwin/include
-I/usr/sfw/include -I/usr/sfw/include/freetype2 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include   -I/usr/local/include/xfce4 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -g -O2 -MT libxfce4mixer_la-vc_sun.lo -MD -MP -MF
".deps/libxfce4mixer_la-vc_sun.Tpo" -c -o libxfce4mixer_la-vc_sun.lo `test -f
'vc_sun.c' || echo './'`vc_sun.c; \
then mv -f ".deps/libxfce4mixer_la-vc_sun.Tpo"
".deps/libxfce4mixer_la-vc_sun.Plo"; else rm -f
".deps/libxfce4mixer_la-vc_sun.Tpo"; exit 1; fi
 gcc -DHAVE_CONFIG_H -I. -I. -I.. -I../include -I/usr/include/gtk-2.0
-I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/pango-1.0
-I/usr/openwin/include -I/usr/sfw/include -I/usr/sfw/include/freetype2
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/local/include/xfce4
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -g -O2 -MT
libxfce4mixer_la-vc_sun.lo -MD -MP -MF .deps/libxfce4mixer_la-vc_sun.Tpo -c
vc_sun.c  -fPIC -DPIC -o .libs/libxfce4mixer_la-vc_sun.o
vc_sun.c:85: warning: static declaration of 'vc_reinit_device' follows
non-static declaration
vc_sun.c:72: warning: previous implicit declaration of 'vc_reinit_device' was here
vc_sun.c:94: error: conflicting types for 'vc_set_device'
vc_sun.c:71: error: previous implicit declaration of 'vc_set_device' was here
make[2]: *** [libxfce4mixer_la-vc_sun.lo] Error 1
make[2]: Leaving directory `/root/xfce-build/xfce4-mixer/lib'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/root/xfce-build/xfce4-mixer'
make: *** [all] Error 2





 # gcc -v
Reading specs from /usr/sfw/lib/gcc/sparc-sun-solaris2.10/3.4.3/specs
Configured with:
/gates/sfw10/builds/sfw10-gate/usr/src/cmd/gcc/gcc-3.4.3/configure
--prefix=/usr/sfw --with-as=/usr/sfw/bin/gas --with-gnu-as
--with-ld=/usr/ccs/bin/ld --without-gnu-ld --enable-languages=c,c++ --enable-shared
Thread model: posix
gcc version 3.4.3 (csl-sol210-3_4-branch+sol_rpath)