需要帮助设置RubyonRails javascript运行时环境吗

在我的机器上设置ruby on rails时遇到问题。我一直在关注《使用Rails进行敏捷Web开发》一书，到目前为止，一切都进展顺利

我的问题是当我打字的时候

rails server

我得到以下错误：

/home/myname/.gem/ruby/1.9.1/gems/execjs-1.3.0/lib/execjs/runtimes.rb:50:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
from /home/myname/.gem/ruby/1.9.1/gems/execjs-1.3.0/lib/execjs.rb:5:in `<module:ExecJS>'
from /home/myname/.gem/ruby/1.9.1/gems/execjs-1.3.0/lib/execjs.rb:4:in `<top (required)>'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `require'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `<top (required)>'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `require'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `<top (required)>'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1:in `require'
from /usr/lib/ruby/gems/1.9.1/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1:in `<top (required)>'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:68:in `require'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:66:in `each'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:66:in `block in require'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:55:in `each'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler/runtime.rb:55:in `require'
from /home/myname/.gem/ruby/1.9.1/gems/bundler-1.1.0/lib/bundler.rb:118:in `require'
from /home/myname/Programming/Learning/Learning_Rails/demo/config/application.rb:7:in `<top (required)>'
from /home/myname/.gem/ruby/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:53:in `require'
from /home/myname/.gem/ruby/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:53:in `block in <top (required)>'
from /home/myname/.gem/ruby/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:50:in `tap'
from /home/myname/.gem/ruby/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

当我运行“gem list”时，我得到以下输出：

*** LOCAL GEMS ***

actionmailer (3.2.2)
actionpack (3.2.2)
activemodel (3.2.2)
activerecord (3.2.2)
activeresource (3.2.2)
activesupport (3.2.2)
arel (3.0.2)
bigdecimal (1.1.0)
builder (3.0.0)
bundler (1.1.0)
coffee-rails (3.2.2)
coffee-script (2.2.0)
coffee-script-source (1.2.0)
erubis (2.7.0)
execjs (1.3.0 ruby)
hike (1.2.1)
i18n (0.6.0)
io-console (0.3)
journey (1.0.3)
jquery-rails (2.0.1)
json (1.6.5, 1.5.4)
mail (2.4.3)
mime-types (1.17.2)
minitest (2.11.3, 2.5.1)
multi_json (1.1.0)
polyglot (0.3.3)
rack (1.4.1)
rack-cache (1.2)
rack-ssl (1.3.2)
rack-test (0.6.1)
rails (3.2.2)
railties (3.2.2)
rake (0.9.2.2)
rdoc (3.12, 3.9.4)
sass (3.1.15)
sass-rails (3.2.4)
sprockets (2.3.1, 2.1.2)
sqlite3 (1.3.5)
thor (0.14.6)
tilt (1.3.3)
treetop (1.4.10)
tzinfo (0.3.32)
uglifier (1.2.3)

从上面的输出来看，我觉得好像安装了execjs。这里发生了什么，为什么我会出现这个错误

如果有帮助的话

我的操作系统是ArchLinux

ruby-v:ruby 1.9.3p125（2012-02-16修订版34643）[x86_64-linux]

轨道-v:rails 3.2.2

---

任何帮助都将不胜感激。

我认为您需要像rubyracer这样的运行时。 试一试

---

您的文件应包含以下两行：

gem 'execjs'
gem 'therubyracer'

---

然后运行

bundle install

并重试。

如果您要添加Rubyracer gem，您的问题可能会得到解决

代码

然后只需执行

捆绑安装

尝试以下操作：

$ sudo apt-get install nodejs

---

如果您使用Pacman数据包管理器，则应使用：

# pacman -S nodejs 

或

---

我在Rails之前安装了Node.js。现在它自己使用Node.js作为javascript运行时

JavaScript Runtime  Node.js (V8)

---

我试过了，结果是：

$bundle install execjs“install”调用不正确。调用为“bundle install”。

编辑以指定js运行时。rubyracer不会出现在gem列表输出中。你确定已经安装了吗？我运行了sudo gem安装therubyracer。它看起来像是在安装，总的来说大约需要5分钟。安装时没有任何错误消息，之后我运行了sudogem更新。我错过了一个步骤吗？我尝试运行gem'therubyracer'命令，但是我得到一个错误，说therubyracer是一个未知的命令。如果我运行gem'execjs'，也会发生同样的情况。我误解你了吗？

$ sudo apt-get install nodejs

# pacman -S nodejs 

$ sudo pacman -S nodejs

JavaScript Runtime  Node.js (V8)