Installing PostgreSQL 8.4.x (8.4.8-1) and 9.x (9.0.4-1) on OS X Lion with EnterpriseDB installer (fix)

Postgres for Mac OS X has three install options:

  1. Using a package management system. Fink, MacPorts and Homebrew all have it. I've tried only MacPorts and it works fine.
  2. Manually downloading and compiling it.
  3. Using EntrepriseDB's installer. It can be found here.
Options 1) and 2) require Xcode. Xcode is a large development package for OS X. It installs an IDE, compilers and unix tools. Options 1) and 2) use the unix tools.
I don't want to install Xcode, even though there is a way to limit it's memory footprint. Here's how (the question was with negative rating when I found it, but the answer is useful).
Anyway I don't want to install Xcode, and on my last OS X I only installed a couple of databases. That made the whole ports thing a bit useless.
So I tried the EnterpriseDB's installer. It failed with
Problem running post-install step. Installation may not complete correctly
The database cluster initialisation failed.
The official sites said: Lion is not yet supported: link. I didn't want to install some package management solution so I wanted a solution.
I found one here. On a poker site - kill me now. It seems to be the easiest one. Just create a postgres user using the Users & Groups preference tab. Don't create a Sharing only user, it doesn't work with it - I tried. Create a normal user. Everything works like a charm:
I tried the new postgres 9.0.4, but it failed with "invalid stream header: BB656430" when serving binary data from an import from 8.4.x. I went back to 8.4.x.
EntrepriseDB's installer creates an uninstaller, installs pgAdmin, works nice. User-friendly.