I’m curious whether you searched for the error (Postgrex.Error) FATAL 28000 (invalid_authorization_specification) role "postgres" does not exist as the first result for me is a thread on this forum:
For anyone coming to this thread in future this is how I install Postgres on a new machine:
# Install with:
brew install postgresql
# Then to start Postgres and on startup, run:
brew services start postgresql@14
# Then create your initial db:
createdb
# Then:
psql
CREATE ROLE postgres LOGIN CREATEDB;
# That will create your Postgres user (use CTRL Z to exit).
