在“require”中:没有要加载的此类文件——iconv (LoadError)

    ➜  expertiza git:(master) ✗ ruby -v
    ruby 1.8.7 (2011-06-30 patchlevel 352) [i686-darwin11.1.0]
    ➜  expertiza git:(master) ✗ rails -v
    Rails 2.3.14
    ➜  expertiza git:(master) ✗ script/server
/Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/inflector.rb:3:in `require': no such file to load -- iconv (LoadError)
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/inflector.rb:3
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext/integer/inflections.rb:1:in `require'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext/integer/inflections.rb:1
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext/integer.rb:2:in `require'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext/integer.rb:2
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext.rb:8:in `require'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext.rb:8
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext.rb:8:in `each'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support/core_ext.rb:8
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support.rb:56:in `require'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/activesupport-2.3.14/lib/active_support.rb:56
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/rails-2.3.14/lib/commands/server.rb:1:in `require'
    from /Users/HPV/.rvm/gems/ruby-1.8.7-p352/gems/rails-2.3.14/lib/commands/server.rb:1
    from script/server:3:in `require'
    ➜  expertiza git:(master) ✗ ruby -v
    rub