pg_receivexlog renamed to pg_receivewal #
    PostgreSQL 9.6 and below provided a command named
    pg_receivexlog
    
    to fetch write-ahead-log (WAL) files.  This command was renamed to pg_receivewal, see
    pg_receivewal for documentation of pg_receivewal and see
    the release notes for PostgreSQL 10 for details
    on this change.