server not starting with ruby 1.9.1

i had ruby 1.8.7 in my system.(Ubuntu 9.04)
Rails version is 2.1.0
now i have installed ruby 1.9.1p129 side by side with 1.8.7

$ ruby -v
ruby 1.9.1p129 (2009-05-12 revision 23412) [i686-linux]

nd i,ve also done the following:
$ sudo gem install rails

now
$ gem list

*** LOCAL GEMS ***

actionmailer (2.3.3)
actionpack (2.3.3)
activerecord (2.3.3)
activeresource (2.3.3)
activesupport (2.3.3)
rack (1.0.0)
rails (2.3.3)
rake (0.8.7)

now i'm not able to start server for the application which i had
developed using ruby 1.8.7 ..i.e.
now when i do 'ruby script/server'

following error comes:-
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_support/vendor.rb:33:in
`require': no such file to load -- builder (LoadError)
from
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_support/vendor.rb:33:in
`rescue in <top (required)>'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_support/vendor.rb:2:in
`<top (required)>'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_support.rb:26:in
`require'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_support.rb:26:in
`<top (required)>'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/commands/server.rb:1:in
`require'

and on doing
$ ruby script/console
i got:

Loading development environment (Rails 2.1.0)
/opt/ruby1.9/lib/ruby1.9/1.9.1/irb/completion.rb:9:in
`require':LoadError: no such file to load -- readline
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/initializer.rb:225:in
`rescue in require_frameworks': no such file to load -- builder
(RuntimeError)
from
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/initializer.rb:222:in
`require_frameworks'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/initializer.rb:113:in
`process'
from
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/initializer.rb:93:in
`run'
from /home/abhi/Rails_Projects/Blog/config/environment.rb:13:in `<top
(required)>'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb/init.rb:262:in `require'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb/init.rb:262:in `block in
load_modules'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb/init.rb:260:in `each'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb/init.rb:260:in `load_modules'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb/init.rb:20:in `setup'
from /opt/ruby1.9/lib/ruby1.9/1.9.1/irb.rb:53:in `start'
from /usr/local/bin/irb:12:in `<main>'

from
/home/abhi/Rails_Projects/Blog/vendor/rails/railties/lib/commands/server.rb:1:in
`<top (required)>'
from script/server:3:in `require'
from script/server:3:in `<main>'

following error comes:-
/home/abhi/Rails_Projects/Blog/vendor/rails/activesupport/lib/active_suppor t/vendor.rb:33:in
`require': no such file to load -- builder (LoadError)

Sounds like you've got some missing gems (your ruby 1.9 and ruby 1.8
installations will put their gems in separate places)

Fred

Did you migrate your application to Rails 2.3.3?

Rick Lloyd wrote:

Did you migrate your application to Rails 2.3.3?

On Sep 3, 5:38�am, Abhishek Singh <rails-mailing-l...@andreas-s.net>

how to migrate my application to rails 2.3.3

when i do script/console it still shows :

Loading development environment (Rails 2.1.0)
and then error.

while when i created new project now then it is using rails 2.3.3
but old one is still using rails 2.1.0???

-abhishek

Rick Lloyd wrote:

Did you migrate your application to Rails 2.3.3?

On Sep 3, 5:38�am, Abhishek Singh <rails-mailing-l...@andreas-s.net>

how to migrate my application to rails 2.3.3

See http://wiki.rubyonrails.org/getting-started/upgrading

Colin