centos 上安装问题，启动不了 WEBRick

ould not find gem 'turn (= 0.8.2) ruby' in any of the gem sources listed in your Gemfile.

这个turn 0.8.2怎么弄出来。

我的GEMS。turn 0.8.3，我晕了。

*** LOCAL GEMS ***

actionmailer (3.1.3)
actionpack (3.1.3)
activemodel (3.1.3)
activerecord (3.1.3)
activeresource (3.1.3)
activesupport (3.1.3)
ansi (1.4.1)
arel (2.2.1)
builder (3.0.0)
bundler (1.0.21)
coffee-rails (3.1.1)
coffee-script (2.2.0)
coffee-script-source (1.1.3)
erubis (2.7.0)
execjs (1.2.9)
hike (1.2.1)
i18n (0.6.0)
jquery-rails (1.0.18)
json (1.6.1)
mail (2.3.0)
mime-types (1.17.2)
minitest (1.6.0)
multi_json (1.0.3)
polyglot (0.3.3)
rack (1.3.5)
rack-cache (1.1)
rack-mount (0.8.3)
rack-ssl (1.3.2)
rack-test (0.6.1)
rails (3.1.3)
railties (3.1.3)
rake (0.9.2.2, 0.8.7)
rdoc (3.11, 2.5.8)
sass (3.1.10)
sass-rails (3.1.5)
sprockets (2.0.3)
sqlite3 (1.3.4)
sqlite3-ruby (1.3.3)
thor (0.14.6)
tilt (1.3.3)
treetop (1.4.10)
turn (0.8.3)
tzinfo (0.3.31)