I just had exactly the same problem installing the ruby-postgres-0.7.1 gem,
which I -believe- is the latest version of what used to just be called the
"postgres" gem. It seemed to install, yet 'require "postgres'" failed.
I'm using Postgres 8.1 on Ubuntu 6.06. I'd previously used Postgres 8.0 on
Mandrake 10 with no problems.
Torkel, which Postgres and what OS?
Can anyone confirm my recollection that ruby-postgres is the rightful
descendant of postgres? The postgres gem itself wouldn't build on my
system, as it depends on libpq-fe.h which is apparently missing from 8.1
(or at least Ubuntu's packaging of it).