At home, I’m a Linux user but at work most companies use Mac for engineers. It’s been
a couple years since I’ve used Mac so I’m learning my way back around it along with
Homebrew. One issue I ran into the other day was postgresql service not starting
sucessfully. No amount of brew services restart postgresql would fix it. Turns
out to be a pretty simple fix.
I first noticed the issue when trying to run a Ruby on Rails server locally. The response
from running rails s looked something like:
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
Alright, so this is saying the server isn’t running or listening to requests. Checking
brew services list to see the output rendered:

Next was looking up what a 256 error which led me to an excellent StackOverflow post. Following the post suggested three step process of: stopping the service, removing the pid file, and restarting the service.

The pid file can be found in one of two locations:
/usr/local/var/postgres/postmaster.pid/opt/homebrew/var/postgresql/postmaster.pid(Apple M1)
I found mine within the /opt/ directory. Last was just restarting the service.

After this running rails s worked as expected.
Thanks for reading it was a quick one.
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