file.c:1242
NORETURN(static void sys_fail2 _((VALUE,VALUE)));
static void
sys_fail2(s1, s2)
    VALUE s1, s2;
{
    char *buf;
    int len;

    len = RSTRING(s1)->len + RSTRING(s2)->len + 5;
    buf = ALLOCA_N(char, len);
    snprintf(buf, len, "%s or %s", RSTRING(s1)->ptr, RSTRING(s2)->ptr);
    rb_sys_fail(buf);
}
