问题
I've been trying to use Rails and when I use rake, I get this error. Any suggestions on which run time should I use?
ngzhongqin@ngzhongqin-linux:~/RailsProjects/webuiltit$ rake db:create:all --trace
rake aborted!
Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes.
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/execjs-1.2.4/lib/execjs/runtimes.rb:45:in `autodetect'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/execjs-1.2.4/lib/execjs.rb:5:in `<module:ExecJS>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/execjs-1.2.4/lib/execjs.rb:4:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-rails-3.1.0/lib/coffee-rails.rb:1:in `require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/coffee-rails-3.1.0/lib/coffee-rails.rb:1:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:68:in `require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:66:in `each'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:66:in `block in require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:55:in `each'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler/runtime.rb:55:in `require'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/bundler-1.0.18/lib/bundler.rb:120:in `require'
/home/ngzhongqin/RailsProjects/webuiltit/config/application.rb:13:in `<top (required)>'
/home/ngzhongqin/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/home/ngzhongqin/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
/home/ngzhongqin/RailsProjects/webuiltit/Rakefile:5:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/rake_module.rb:25:in `load'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/rake_module.rb:25:in `load_rakefile'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:495:in `raw_load_rakefile'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:78:in `block in load_rakefile'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:77:in `load_rakefile'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:61:in `block in run'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2/bin/rake:32:in `<top (required)>'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `load'
/home/ngzhongqin/.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `<main>'
回答1:
You need to install runtime for these.. some of the good options are
therubyracer - Google V8 embedded within Ruby
therubyrhino - Mozilla Rhino embedded within JRuby
Johnson - Mozilla SpiderMonkey embedded within Ruby
Mustang - Mustang V8 embedded within Ruby
Node.js
Apple JavaScriptCore - Included with Mac OS X
Mozilla SpiderMonkey
Microsoft Windows Script Host (JScript)
you can find more details at https://github.com/sstephenson/execjs
回答2:
Add this to your Gemfile
gem 'therubyracer', require: "v8"
and run
bundle install
回答3:
I have installed the gem therubyracer, execjs, mustang but nothing worked.
On my linux (ubuntu) the command
sudo apt-get install nodejs
did the job finally for me.
May be this post could also be helpful: https://github.com/intridea/rails_wizard/issues/31
来源：https://stackoverflow.com/questions/7376021/rails-rake-does-not-work