Installation is success but the path variable is not exported instantly, so the psql command is not found on line 363 of version 5 rc2 (line 352 of version 4). It can be circumvented by manually exporting the path before executing (or rerun the script after logging on and off). Thus, not severe but might be worth fixing or explaining it?
Possibly the path variable could be exported within the current session in addition to writing them to the .bashr?
Reported by: osm user g0ldfish
System: fUbuntu 10.10 (fresh installation with default settings)