can't compile basic hello world on RHEL

I must be missing something major, because I can't get the following
simple program to compile:

#include <stdio.h>

int main(){
fprintf(stderr,"Hello world\n");

The error I get from doing "gcc -o testme testme.c" is:

/tmp/ccMJ0qjZ.o(.text+0x28): In function `main':
: undefined reference to `__getreent'
collect2: ld returned 1 exit status

I already did "up2date gcc" and "up2date compat-gcc-32-c++", but I
still get the same error. If I try to compile this on a Mac OS X
system, or on another linux system we have, everything is fine.

Does anyone have a clue as to what's going on?