rails -v got error??? already initialized constant

i got a trouble , in an rails project（redmine2.3）, rails version is 3.2

start the project bundle exec thin start -p 8080 -e production -s 5 -d

error info (eval):9: warning: already initialized constant Bundler::Dsl::RAILS_VERSION_IS_3 (eval):9: warning: previous definition of RAILS_VERSION_IS_3 was here (eval):9: warning: already initialized constant Bundler::Dsl::RAILS_VERSION_IS_3 (eval):9: warning: previous definition of RAILS_VERSION_IS_3 was here Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby' /var/wtn/vendor/cache/ruby/2.0.0/gems/eventmachine-1.0.3/lib/eventmachine.rb:8:in `require': libruby.so.2.0: cannot open shared object file: No such file or directory - /var/wtn/vendor/cache/ruby/2.0.0/gems/eventmachine-1.0.3/lib/rubyeventmachine.so (LoadError) from /var/wtn/vendor/cache/ruby/2.0.0/gems/eventmachine-1.0.3/lib/eventmachine.rb:8:in `<top (required)>' from /var/wtn/vendor/cache/ruby/2.0.0/gems/thin-1.6.2/lib/thin.rb:7:in `require' from /var/wtn/vendor/cache/ruby/2.0.0/gems/thin-1.6.2/lib/thin.rb:7:in `<top (required)>' from /var/wtn/vendor/cache/ruby/2.0.0/gems/thin-1.6.2/bin/thin:5:in `require' from /var/wtn/vendor/cache/ruby/2.0.0/gems/thin-1.6.2/bin/thin:5:in `<top (required)>' from /var/wtn/vendor/cache/ruby/2.0.0/bin/thin:23:in `load' from /var/wtn/vendor/cache/ruby/2.0.0/bin/thin:23:in `<main>'

seems like there is another rails ？

wtf! why?

rails -v

the same error info rails -v (eval):9: warning: already initialized constant Bundler::Dsl::RAILS_VERSION_IS_3 (eval):9: warning: previous definition of RAILS_VERSION_IS_3 was here

use bundle exec ..... in the project got the same trouble

WHY? How to solve?

I have to start the rails server.