On Sat, 2007-02-03 at 23:55 +0900, Damian Terentyev wrote:
> Gem files will remain installed in 
> /usr/local/lib/ruby/gems/1.8/gems/postgres-0.7.1 for inspection.

Hm, seems like it's not finding the PostgreSQL header and object files.
You can probably get it to work by moving into that directory
(/usr/local/lib/ruby/gems/1.8/gems/postgres-0.7.1) and running:

ruby extconf.rb --with-pgsql-include-dir=/path/to/pgsql/headers
--with-pgsql-lib-dir=/path/to/pgsql/shared_libs

and then run "make" and "make install".

Yours,

Tom