newbie Q: why doesn't this build in Xcode?

[stuudent]

The code below fails utterly in Xcode. Obviously, I'm new to Xcode.

Have checked all the build options. Turned off ZeroLink. Set paths for postgresql82 header and library. Set custom linker option -lpq.

// main.c
#include <libpq-fe.h>
int main (int argc, char * const argv[]) {
	PGconn *conn = PQconnectdb(NULL);
	PQfinish(conn);	
	return 0;
}

But same file compiles and links fine in gcc!
gcc -Wall -I/opt/local/include/postgresql82 -L/opt/local/lib/postgresql82 main.c -lpq -o hello

What gives?

-- stuudent