ERROR: could not load library "/usr/local/pgsql/lib/postgres_fdw.so": dlopen(/usr/local/pgsql/lib/postgres_fdw.so, 10): Symbol not found: _ExecProcNode Referenced from: /usr/local/pgsql/lib/postgres_fdw.so Expected in: /usr/local/pgsql/bin/postgres in /usr/local/pgsql/lib/postgres_fdw.so
Apparently you're using an old version of postgres_fdw with a v10 core server.