## The problem
Issue heroku/cli#2563 (closed, 16 comments): HI.

This week the `heroku pg:pull` command stopped working and it returns:

```
heroku-cli: Pulling postgresql-metric-35199 ---> aposta10_development
pg_dump: error: connection to server at "ec2-54-160-95-35.compute-1.amazonaws.com" (54.160.95.35), port 5432 failed: FATAL:  no PostgreSQL user name specified in startup packet
connection to server at "ec2-54-160-95-35.compute-1.amazonaws.com" (54.160.95.35), port 5432 failed: FATAL:  no PostgreSQL user name specified in startup packet
pg_restore: error: could not read from input file: end of file
 ▸    pg_dump errored with...

## What fixed it
[alexandregaldeano (commenter)]: The FATAL: no PostgreSQL user name specified in startup packet errors with heroku pg:psql on macOS come from a broken Homebrew libpq. Fix with brew upgrade libpq, confirmed by multiple reporters. The Heroku team's fallback advice: install PostgreSQL via postgresapp.com instead of Homebrew.