/tmp/.s.PGSQL.5432 is the Unix socket.

It is time the year to figure out the answer of:

PG::ConnectionBad: 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"?

Check if Postgres started:

ps aux | grep postgres

I’ve collected all possible answers, try any of these combinations. Good luck!

Solution 1

brew services restart postgresql

Solution 2

This main postgres process exit but did not clear this file so postgres thought it already started, remove this file:

rm /usr/local/var/postgres/postmaster.pid

then brew services restart postgresql.

2019 ✅

Solution 3

Could be there is no default database:

initdb --locale=C -E UTF-8 $HOMEBREW_PREFIX/var/postgres
pg_ctl -D $HOMEBREW_PREFIX/var/postgres -l logfile start

2020 ✅

Solution 4

If you recently brew upgrade then maybe you need this:

brew postgresql-upgrade-database

Article with more details

2020 ✅

Solution 5

Restart your computer.

Solution 6

Try bin/postgres-broke.

Solution 7

2020-06-16 11:36:26.805 [6532] LOG:  database system is ready to accept connections
2020-06-16 11:36:50.010 [6846] WARNING:  SET LOCAL can only be used in transaction blocks
2020-06-16 11:36:50.010 [6846] WARNING:  SET LOCAL can only be used in transaction blocks
dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.64.dylib
  Referenced from: /usr/local/opt/postgresql/bin/postgres
  Reason: image not found
dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.64.dylib
  Referenced from: /usr/local/opt/postgresql/bin/postgres
  Reason: image not found
dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.64.dylib
  Referenced from: /usr/local/opt/postgresql/bin/postgres
  Reason: image not found

Reinstall:

$ brew uninstall --force postgresql
$ brew install postgresql

Solution 8

You recently brew upgrade, PostgreSQL’s dependency icu4c is broken. Try this command:

initdb --locale=C -E UTF-8 $HOMEBREW_PREFIX/postgres

If you get something similar to:

dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.66.dylib
  Referenced from: /usr/local/Cellar/postgresql/12.3/bin/postgres
  Reason: image not found
no data was returned by command ""/usr/local/Cellar/postgresql/12.3/bin/postgres" -V"
initdb: error: The program "postgres" is needed by initdb but was not found in the
same directory as "/usr/local/Cellar/postgresql/12.3/bin/initdb".
Check your installation.

or

dyld[9404]: Library not loaded: /opt/homebrew/opt/icu4c/lib/libicui18n.69.dylib
  Referenced from: /opt/homebrew/Cellar/postgresql/14.1_1/bin/postgres
  Reason: tried: '/opt/homebrew/opt/icu4c/lib/libicui18n.69.dylib' (no such file), '/usr/local/lib/libicui18n.69.dylib' (no such file), '/usr/lib/libicui18n.69.dylib' (no such file), '/opt/homebrew/Cellar/icu4c/70.1/lib/libicui18n.69.dylib' (no such file), '/usr/local/lib/libicui18n.69.dylib' (no such file), '/usr/lib/libicui18n.69.dylib' (no such file)
no data was returned by command ""/opt/homebrew/Cellar/postgresql/14.1_1/bin/postgres" -V"
initdb: error: The program "postgres" is needed by initdb but was not found in the
same directory as "/opt/homebrew/Cellar/postgresql/14.1_1/bin/initdb".
Check your installation.

Reinstall icu4c:

brew reinstall icu4c

Solution 9

$ brew services start postgres
Bootstrap failed: 5: Input/output error
Try re-running the command as root for richer errors.
Error: Failure while executing; `/bin/launchctl bootstrap gui/501 /Library/LaunchAgents/homebrew.mxcl.postgresql.plist` exited with 5.

$ sudo /bin/launchctl bootstrap gui/501 /Library/LaunchAgents/homebrew.mxcl.postgresql.plist
Password:
/Library/LaunchAgents/homebrew.mxcl.postgresql.plist: service already bootstrapped
Bootstrap failed: 37: Operation already in progress

$ brew services restart postgresql
==> Successfully stopped `postgresql` (label: homebrew.mxcl.postgresql)
==> Successfully started `postgresql` (label: homebrew.mxcl.postgresql)