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Chris Fordham edited this page Sep 4, 2013 · 17 revisions

Installation is through Rubygems while Redcar is under development. Platform installers are on the roadmap for 1.0.




gem install redcar



  • Rubygems (on Ubuntu install package rubygems1.8)
  • Java (on Ubuntu install package openjdk-6-jre)
  • Gecko (on Ubuntu install package firefox-dev. See Common Problems if you cannot find this package.)


sudo gem install redcar
rvmsudo gem install redcar (if you are using Fedora Linux)


  • You must have Xcode and Xcode Command Line Tools (available view Xcode > Preferences > Downloads) installed.

sudo gem install redcar

Installing from source for development


  • JRuby


git clone git://
cd redcar
jruby -S bundle install


  • If you want to start redcar via bundle exec (for example if using redcar from your own bundle) then on OSX you must ensure the correct java options get forwarded by setting the JRUBY_OPTS environment variable to include -J-XstartOnFirstThread before running bundle exec, i.e. using bash "export JRUBY_OPTS=-J-XstartOnFirstThread"

Common problems

The gem fails to install with an "Invalid gemspec, illformed requirement YAML::Syck" error.

You need to update your Rubygems installation, there were some issues around gem incompatibility in earlier versions.

I can't install the xulrunner package on Ubuntu

In order to 'see' the Gecko related packages in Synaptic or apt you need to have the "security" source for the latest LTS release (currently 10.04 lucid). This is done by adding deb lucid-security main in your /etc/apt/sources.list) either by hand or through Synaptic->Settings->Repositories->Other Software->Add...)

I’ve installed the gem, but when i try to run redcar i get “redcar: command not found”

You don’t have the Rubygem binary directory in your path. (For instance, Ubuntu may not set this up automatically). You can run Redcar with a full path to the binary (On Ubuntu: /var/lib/gems/1.8/bin/redcar or /var/lib/gems/1.9.1/bin/redcar) or you can add the gem binary directory to your path (On Ubuntu, the directory is /var/lib/gems/1.8/bin or /var/lib/gems/1.9.1/bin). If it still doesn't work try ruby redcar install.

I've installed Redcar as a gem under RVM and need a launcher

There is a nice writeup here by Mat Alan Gilbert on creating a custom Redcar launcher.

Redcar crashes with an error “NoMethodError: undefined method ‘item’ for nil:NilClass”, and previously a message saying “unknown mozilla path (MOZILLA_FIVE_HOME not set)”

If you are on Linux, install xulrunner, which is available on Ubuntu in the xulrunner-1.9.2-dev package. If you are not on Linux, contact the development team.

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