BUG #15735: postgis extension missing

The following bug has been logged on the website:

Bug reference:      15735
Logged by:          ramakrishnan r
Email address:      prakash.ramakrishnan.ap@nielsen.com
PostgreSQL version: 11.2
Operating system:   Red Hat Enterprise Linux Server release 7.3 (Maipo
Description:

Hi Team,

Am trying to install postgis in community edition getting below error please
do the needful.

-bash-4.2$ ./psql -p 5439
psql (11.2)
Type "help" for help.

postgres=# create extension postgis;
ERROR:  could not open extension control file
"/usr/pgsql-11/share/extension/postgis.control": No such file or directory
postgres=#
postgres=#