When FreeBSD world (and kernel) is built using clang, the resulting code generated for vsnprintf in the library libc.so does not work properly, causing a segmentation fault. The problem was discovered when attempting to use java on FreeBSD.

How-To-Repeat: Compile and run the following C code on FreeBSD 9.0-STABLE built with clang:

#include <stdio.h>
#include <string.h>

int main(int nargrs, const char* args[])
{
  const char* msg="Hello World!";
  int length=strlen(msg);
  printf("length is %i\n",length);
  char string0[256];
  char string[256];
  memset(string0,1,256);
  strcpy(string0,msg);
  vsnprintf(string+1,length,"%s",string0);
  printf("%s\n",string);

  return 0;
}

Alternatively, try launching java or javac from jdk16, diablo-jdk16 or openjdk6