Here are the log:
Permission denied - ./script/../config/../tmp/sessions//ruby_sess.
6d3884b6a1a60c03.tmp or ./script/../config/../tmp/sessions//ruby_sess.
6d3884b6a1a60c03.new
D:/Lang/ruby/lib/ruby/1.8/pstore.rb:333:in `rename'
D:/Lang/ruby/lib/ruby/1.8/pstore.rb:333:in `transaction'
D:/Lang/ruby/lib/ruby/1.8/cgi/session/pstore.rb:62:in `initialize'
D:/Lang/ruby/lib/ruby/1.8/cgi/session.rb:273:in `new'
D:/Lang/ruby/lib/ruby/1.8/cgi/session.rb:273:in `initialize'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/cgi_process.rb:123:in `new'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/cgi_process.rb:123:in `session'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/cgi_process.rb:155:in `stale_session_check!'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/cgi_process.rb:110:in `session'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/base.rb:1052:in `assign_shortcuts_without_flash'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/flash.rb:140:in `assign_shortcuts'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/base.rb:424:in `process_without_filters'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/filters.rb:624:in
`process_without_session_management_support'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/session_management.rb:114:in `process'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.3/lib/
action_controller/base.rb:330:in `process'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/dispatcher.rb:
41:in `dispatch'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/webrick_server.rb:
113:in `handle_dispatch'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/webrick_server.rb:
79:in `service'
D:/Lang/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
D:/Lang/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:92:in `each'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start'
D:/Lang/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/webrick_server.rb:
63:in `dispatch'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/commands/servers/
webrick.rb:59
D:/Lang/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
D:/Lang/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/
active_support/dependencies.rb:495:in `require'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/
active_support/dependencies.rb:342:in `new_constants_in'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/
active_support/dependencies.rb:495:in `require'
D:/Lang/ruby/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/commands/server.rb:
39
D:/Lang/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
D:/Lang/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require'
./script/server:3
-e:4:in `load'
-e:4
I think ruby can'T rename the session file but why???