While building nginx version 0.7.66, 0.8.35 or higher on Linux the following warning messages are issued:

warning: `sys_errlist' is deprecated;
    use `strerror' or `strerror_r' instead
warning: `sys_nerr' is deprecated;
    use `strerror' or `strerror_r' instead

This is normal: nginx has to use the deprecated sys_errlist[] and sys_nerr in signal handlers because strerror() and strerror_r() functions are not Async-Signal-Safe.