Postgres sharding installation with citusdb
It looks like pg_shard files are not installed. You will need to build pg_shard from sources and install it using make install within pg_shard source folder. 

Please be aware that pg_shard has reached end of life, and it is included in  recently released (Citus 5.0). 

You can also get Citus from PGDG if you are on RPM based system.


sudo yum install -y
https://download.postgresql.org/pub/repos/yum/9.5/redhat/rhel-6-x86_64/pgdg-ami201503-95-9.5-2.noarch.rpm
sudo yum install -y citus_95