compilation issues

hi all.

i've been interested in PostgreSQL for a while and recently downloaded
version 7. however during compilation on my machine (using gmake and
Solaris 8 x86) i get the following errors:

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gcc -I../../include -I../../backend -Wall -Wmissing-prototypes
-Wmissing-declarations -I.. -c -o stringinfo.o stringinfo.c
stringinfo.c: In function `appendStringInfo':
stringinfo.c:104: `va_list' undeclared (first use in this function)
stringinfo.c:104: (Each undeclared identifier is reported only once
stringinfo.c:104: for each function it appears in.)
stringinfo.c:104: parse error before `args'
stringinfo.c:121: warning: implicit declaration of function `va_start'
stringinfo.c:121: `args' undeclared (first use in this function)
stringinfo.c:124: warning: implicit declaration of function `va_end'
gmake[2]: *** [stringinfo.o] Error 1
gmake[2]: Leaving directory `/opt/local/postgresql-7.0/src/backend/lib'
gmake[1]: *** [lib.dir] Error 2
gmake[1]: Leaving directory `/opt/local/postgresql-7.0/src/backend'
gmake: *** [all] Error 2

########

the compilation process prior to this error appeared normal. i have
read the FAQ and did not see a reference to this issue anywhere. do i
need to modify the makefile at all? i ran configure before gmake.

TIA,

Sal