即使已經安裝了Ubuntu，也無法在Ubuntu上啓動Rails服務器

Question

經過多次嘗試修復此問題（安裝rubyracer，更新的gem）並且仍然無法運行服務器。我對新安裝的Ubuntu 12.04，使用Ruby 2.0.0-P247和軌道4.0.0

/home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/execjs-1.4.0/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable) 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/execjs-1.4.0/lib/execjs.rb:5:in `<module:ExecJS>' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/execjs-1.4.0/lib/execjs.rb:4:in `<top (required)>' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/uglifier-2.1.2/lib/uglifier.rb:3:in `require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/uglifier-2.1.2/lib/uglifier.rb:3:in `<top (required)>' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/bundler-1.3.5/lib/bundler.rb:132:in `require' 
from /home/janharold/GIT Repositories/treebook/config/application.rb:7:in `<top (required)>' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:76:in `require' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:76:in `block in <top (required)>' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap' 
from /home/janharold/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>' 
from bin/rails:4:in `require' 
from bin/rails:4:in `<main>' 

Answer 1

顯然，通過獨立安裝的NodeJS，我設法沒有任何問題運行服務器。

詳情在execJs: 'Could not find a JavaScript runtime' but execjs AND therubyracer are in Gemfile