[GRASS5] Grass 5.1 compile error

[cheg01 at attbi.com]

I get the following error building the latest 5.1 source on Solaris 8
Sparc:


make[2]: Entering directory `/usr3/grass51_012403/lib/gis'
gcc -g -Wall  -Wall  -I/usr3/grass51_012403/include -I/usr3/grass51_012403/
dist.sparc-sun-solaris2.8/include     -I/usr3/grass51_012403/include -I/usr
3/grass51_012403/dist.sparc-sun-solaris2.8/include -I/usr/X11R6/include/ -I
/usr/include/gr -I/usr/local/include -I/usr/include  -I/usr/local/pgsql/inc
lude  -I/usr3/grass51_012403/include -I/usr3/grass51_012403/dist.sparc-sun-
solaris2.8/include \
        -o OBJ.sparc-sun-solaris2.8/debug.o -c debug.c

debug.c: In function `G_debug':

debug.c:44: `__builtin_va_alist' undeclared (first use in this function)

Any suggestions?