"I want to hack on this but it wants a postgresql database and i don't want to mess with sudo... can't I just be like 'run a little postgres over here, as me'?"

Yup 👍

export PGDATA="$PWD/pgdata"
export PGHOST="$PGDATA/sockets"

pg_ctl init

mkdir -p "$PGDATA/sockets"
echo "unix_socket_directories = 'sockets'" >> "$PGDATA/postgresql.conf"
echo "listen_addresses = ''" >> "$PGDATA/postgresql.conf"

pg_ctl start

psql # i'm in

some clients might need:

export PGDATABASE="postgres"
export PGUSER="$USER"