Jenkins + Ruby with RVM. Unexpected tCONSTANT error - ruby

Question

We are downloading the latest Cordova documentation and want to generate it with Jenkins.
We are using RVM to manage the Ruby instances.
Here is the relevant shell execution in the Jenkins job.
#!/bin/bash
source "$HOME/.rvm/scripts/rvm"
echo "====== Setting up ruby ========================================"
rvm use "1.7.8"
set -e
echo "====== Installing cordova docs dependencies ==================="
gem install bundler
gem install nokogiri
cd "${WORKSPACE}/submodule_apache_cordova_docs"
bundle install
cd -
echo "====== Generating documents ==================================="
rvm current
ruby -v
${WORKSPACE}/submodule_apache_cordova_docs/bin/generate
and this is the output for that section
[workspace] $ /bin/bash /tmp/hudson1421417307959072745.sh
====== Setting up ruby =====================================
Using /var/lib/jenkins/.rvm/gems/jruby-1.7.8
====== Installing cordova docs dependencies ================
Successfully installed bundler-1.7.2
1 gem installed
Successfully installed nokogiri-1.6.3.1-java
1 gem installed
Fetching gem metadata from https://rubygems.org/.........
Resolving dependencies...
Using json 1.8.1
Using nokogiri 1.5.9
Using rspec 1.3.0
Using bundler 1.7.2
Your bundle is complete!
Use `bundle show [gemname]` to see where a bundled gem is installed.
/var/lib/jenkins/jobs/Build-Documentation/workspace
====== Generating documents ================================
jruby-1.7.8
jruby 1.7.8 (1.9.3p392) 2013-11-14 0ce429e on OpenJDK 64-Bit Server VM 1.7.0_65-b32 [linux-amd64]
SyntaxError: /var/lib/jenkins/jobs/Build-Documentation/workspace/submodule_apache_cordova_docs/bin/../lib/cordova/jodoc.rb:28: syntax error, unexpected tCONSTANT
#template_directories = [ File.join TEMPLATE_PATH, 'default' ]
^
require at org/jruby/RubyKernel.java:1084
require at /var/lib/jenkins/.rvm/rubies/jruby-1.7.8/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:55
require at /var/lib/jenkins/.rvm/rubies/jruby-1.7.8/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:53
(root) at /var/lib/jenkins/jobs/Build-Documentation/workspace/submodule_apache_cordova_docs/bin/../lib/docs_generator.rb:1
require at org/jruby/RubyKernel.java:1084
(root) at /var/lib/jenkins/jobs/Build-Documentation/workspace/submodule_apache_cordova_docs/bin/../lib/docs_generator.rb:26
(root) at /var/lib/jenkins/jobs/Build-Documentation/workspace/submodule_apache_cordova_docs/bin/generate:22
Build step 'Execute shell' marked build as failure
Finished: FAILURE
As far as I can see all the dependency versions are correct, including Ruby.
This is the file that errors: https://github.com/apache/cordova-docs/blob/master/lib/cordova/jodoc.rb
What is causing the error?
Thanks