"Security: Format string is not a string literal" build failure(s) — clang 2.9

The following code builds without any issue with gcc and fails with clang:
#include <stdio.h>

void foo(void) {
    char buffer[1024];
    sprintf(buffer, "%n", 2);
}
gcc -Werror -c foo.c
clang -Werror -c foo.c
PackageVersionSupposed error messageFull log Bug report
dctrl-tools 2.18lib/msg.h:115:24: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security] Log
libgconf-bridge 0.1-2gconf-bridge.c:1180:47: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security] Log
xfce4-power-manager 1.0.10-4xfpm-battery.c:404:37: error: format string is not a string literal (potentially insecure) [-Wformat-security] Log

3 errors