PostgreSQL server cannot bind to any port; "Address already in use"

Build Environment Databases
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1

I run the following command to install PostgreSQL 11

      - run:
          name: Install PostgreSQL
          command: |
            sudo apt-get install -y postgresql-11 postgresql-contrib
            echo 'export PATH=/usr/lib/postgresql/11/bin/:$PATH' >> $BASH_ENV

I modify $PATH to make initdb available; the tests need to create, start, and stop clusters themselves.

I have tried stopping the service with sudo pg_dropcluster --stop 11 main right after installing postgresql-11 but I can’t tell if that even does anything.

2019-09-27 14:42:34.416 UTC [2215] LOG:  could not bind IPv4 address "127.0.0.1": Address already in use
2019-09-27 14:42:34.416 UTC [2215] HINT:  Is another postmaster already running on port 5433? If not, wait a few seconds and retry.
2019-09-27 14:42:34.417 UTC [2215] LOG:  could not bind IPv6 address "::1": Cannot assign requested address
2019-09-27 14:42:34.417 UTC [2215] HINT:  Is another postmaster already running on port 5433? If not, wait a few seconds and retry.

All efforts end the same no matter what port I try.

I’m using the circleci/node:12.10 docker image.