The clnt_spcreateerror routine returns the address of a message
    string. The message consists of the sp parameter followed by an
    error message generated by calling the clnt_sperrno routine. Use
    the clnt_spcreateerror routine when the clnt_create, clnttcp_
    create, or clntudp_create routine fails.

    Use this routine if:
    o  You want to save the string.
    o  You do not want to use fprintf to print the message.
    o  The message format is different from the one that clnt_perrno
       supports.

    The address that clnt_spcreateerror returns is the address of
    its own internal string buffer. The clnt_spcreateerror routine
    overwrites this buffer with each call. Therefore, you must copy
    the string to your own buffer if you wish to save the string.