execJs: 'Could not find a JavaScript runtime&#

Question

I'm getting this error:

rake aborted! Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs,

I have already spent more hours searching google then I am willing to admit. I believe this is an execJs bug.

From all the posts, this is a very common issue with rails 3.1. A js runtime is now needed by what are now standard gems like coffee-script and sass.

Most of these cases were resolved by adding the gems 'execjs' and 'therubyracer' to the app Gemfile, and then running 'bundle update' and/or 'bundle install'. But not for me.

I guess I got lucky. I am running rails 3.1.3/ruby 1.9 on an old version of Redhat Linux 4 (2.6.9-101.ELsmp) and gcc is 3.4.6.

Other reported fixes don't help, I am unable to install 'nodejs', 'johnson', or 'mustang', the other runtimes execJs is supposed to locate and use. They won't make/install on my system.

I need to fix the problem causing execJs to fail to locate 'therubyracer'. Here is the Gemfile (and bundle install says 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

And here is a trace:

~/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>'

There is nothing interesting in the development log.

Here is the execjs dir:

/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  

I have also tried execjs-1.2.13. Same problem.

If I comment execjs.rb below, I can run rake without the error:

require "execjs/module"
require "execjs/runtimes"

module ExecJS
  self.runtime #||= Runtimes.autodetect
end

But then I don't get a runtime.

I can see where the error text comes from in runtimes.rb:

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

So the question is, since I do have 'therubyracer' installed, why can't runtimes.rb find it? Is execJs broken?

Here it 'therubyracer':

/usr/local/lib/ruby/gems/1.9.1/gems/therubyracer-0.9.9

How can I fix this?

Answer 1

Fedora users WILL NOT be able to do a simple "yum install nodejs" due to serious naming and file placement conflicts that prevent this package from even being available through the Fedora repositories.

There is apparently at least one alternate repository available with an alternate build that may work, but that's two too many "alternates" for me to be willing to use it-- I'm looking for another alternative.

Answer 2

I had the same problem on a staging server. I had no issues running rake tasks on my local development machine, but deploying to the staging server failed with the "Could not find a JavaScript runtime" error message while trying to run the assets:precompile rake task.

Of course, therubyracer and execjs were in my Gemfile, and I was using the latest versions. My Gemfile.lock files matched, and I further verified versions by running bundle show.

After searching around on Google, I ended up deleting all of my gems and reinstalling them which fixed the problem. I still don't know what the root cause was, but maybe this will help you.

Here's what my environment looks like, BTW:

Ubuntu 10.04.3 LTS
rbenv
Ruby 1.9.2-p290
bundler-1.0.21
execjs-1.3.0
therubyracer-0.9.9

Answer 3

If you were on ubuntu $ sudo apt-get install nodejs

Try to don't use another systems like Windows to development. Think that almost all servers in the world are Linux servers, so when you try to deploy that application it will be easier if you have developed that on a Linux or Unix environment too.

Answer 4

This is the link I needed to fix the problem (install nodejs): https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager

Answer 5

I had the same problem. Adding the gems 'execjs' and 'therubyracer' not work for me. apt-get install nodejs - also dosn't works. I'm using 64bit ubuntu 10.04.

But it helped me the following: 1. I created empty folder (for example "java"). 2. From the terminal in folder that I created I do:

$ git clone git://github.com/ry/node.git
$ cd node
$ ./configure
$ make
$ sudo make install

After that I run "bundle install" as usual (from folder with ruby&rails project). And the problem was resolved. Ruby did not have to reinstall.

Answer 6

Try installing NodeJS and try again.

https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager