手動安裝 gem .

來源: http://stackoverflow.com/questions/8991963/why-does-therubyracer-fails-to-build-on-my-debian

1. Clone therubyracer's source git clone https://github.com/cowboyd/therubyracer.git
2. Checkout tag v0.9.8 git checkout v0.9.8
3. Change version number in ./lib/v8/version.rb to 0.9.9
4. Build the gem gem build therubyracer.gemspec
5. Install the gem gem install therubyracer-0.9.9.gem