Since postgresql@9.6 is EoL and deprecated by Homebrew, an alternative is to use the PostgresApp. The app comes bundled with a handful of versions of postgresql.
After installing the app via the mac.sh script, you will need to initialize the DB manually. Follow this guide for how to do that.
- Open the PostgresApp however you like. It should be in your
/Applications
directory
- Select the
+
button on the bottom left of the Left Sidebar
-
Name the server
local
(or whatever name you want) and then choose9.6
for the version -
Click
Create Server
- Click
Initialize
- You're Done!