我收到此错误：
耙子流产了！找不到JavaScript运行时。参见https://github.com/sstephenson/execjs，
我已经花了更多时间搜索Google，然后我愿意承认。我相信这是execJs的错误。
从所有帖子来看，这是Rails 3.1的一个非常普遍的问题。现在，标准的宝石（例如coffee-script和sass）需要js运行时。
通过将Gems'execjs'和'therubyracer'添加到应用程序Gemfile中，然后运行'bundle update'和/或'bundle install'，可以解决大多数情况。但是不适合我。
我想我很幸运。我在旧版本的Redhat Linux 4（2.6.9-101.ELsmp）上运行rails 3.1.3 / ruby 1.9，gcc是3.4.6。
其他报告的修复程序无济于事，我无法安装'nodejs'，'johnson'或'mustang'，而其他运行时execJs应该定位并使用。他们不会在我的系统上安装/安装。
我需要解决导致execJ找不到'therubyracer'的问题。这是Gemfile（并且安装包显示OK）：
source 'http://rubygems.org'
gem 'rails', '3.1.3'
gem 'sqlite3'
gem 'sho-mongrel'
gem 'execjs'
gem 'therubyracer'
#gem "therubyracer", :require => 'v8'
group :assets do
gem 'sass-rails', '~> 3.1.5'
gem 'coffee-rails', '~> 3.1.1'
gem 'uglifier', '>= 1.0.3'
end
这是一个痕迹：
~/rails/316-private-pub/chatter-after>rake db:create --trace
rake aborted!
Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes.
/usr/local/lib/ruby/gems/1.9.1/gems/execjs-1.3.0/lib/execjs/runtimes.rb:50:in `autodetect'
/usr/local/lib/ruby/gems/1.9.1/gems/execjs-1.3.0/lib/execjs.rb:5:in `<module:ExecJS>'
/usr/local/lib/ruby/gems/1.9.1/gems/execjs-1.3.0/lib/execjs.rb:4:in `<top (required)>'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `require'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:66:in `block in require'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler/runtime.rb:55:in `require'
/usr/local/lib/ruby/gems/1.9.1/gems/bundler-1.0.21/lib/bundler.rb:122:in `require'
/home/vitalarthur/rails/316-private-pub/chatter-after/config/application.rb:7:in `<top (required)>'
/usr/local/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/usr/local/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/home/vitalarthur/rails/316-private-pub/chatter-after/Rakefile:5:in `<top (required)>'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load_rakefile'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `block in load_rakefile'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `block in run'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/usr/local/lib/ruby/gems/1.9.1/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/usr/local/bin/rake:19:in `load'
/usr/local/bin/rake:19:in `<main>'
开发日志中没有有趣的东西。
这是execjs目录：
/usr/local/lib/ruby/gems/1.9.1/gems/execjs-1.3.0/lib/execjs>ls
disabled_runtime.rb module.rb ruby_rhino_runtime.rb version.rb
external_runtime.rb mustang_runtime.rb runtimes.rb
johnson_runtime.rb ruby_racer_runtime.rb
我也尝试过execjs-1.2.13。同样的问题。
如果我在下面评论execjs.rb，则可以运行rake而不出现错误：
require "execjs/module"
require "execjs/runtimes"
module ExecJS
self.runtime #||= Runtimes.autodetect
end
但是然后我没有运行时。
我可以在runtimes.rb中看到错误文本的来源：
def self.autodetect
from_environment || best_available ||
raise(RuntimeUnavailable, "Could not find a JavaScript runtime. " +
"See https://github.com/sstephenson/execjs for a list of available runtimes.")
end
所以问题是，由于我确实安装了'therubyracer'，为什么runtimes.rb无法找到它？execJs坏了吗？
这里是“ therubyracer”：
/usr/local/lib/ruby/gems/1.9.1/gems/therubyracer-0.9.9我怎样才能解决这个问题？