bundler error

bundle-env.txt

# bundle env
Bundler 1.6.0
Ruby 2.1.1 (2014-02-24 patchlevel 76) [x86_64-linux]
Rubygems 2.2.2
GEM_HOME

Bundler settings
  path
    Set for your local app (/code/github.com/sanemat/snake.tachikoma.io/.bundle/config): "vendor/bundle"
  disable_shared_gems
    Set for your local app (/code/github.com/sanemat/snake.tachikoma.io/.bundle/config): "1"


Gemfile
source 'https://rubygems.org'
gem 'byebug'
# Specify your gem's dependencies in snake.gemspec
gemspec


Gemfile.lock
PATH
  remote: .
  specs:
    snake (0.0.1)
      oj
      tachikoma
      thor


GEM
  remote: https://rubygems.org/
  specs:
    addressable (2.3.6)
    byebug (2.7.0)
      columnize (~> 0.3)
      debugger-linecache (~> 1.2)
    columnize (0.3.6)
    debugger-linecache (1.2.0)
    faraday (0.9.0)
      multipart-post (>= 1.2, < 3)
    json (1.8.1)
    multipart-post (2.0.0)
    octokit (2.7.2)
      sawyer (~> 0.5.2)
    oj (2.6.1)
    rake (10.1.1)
    safe_yaml (1.0.1)
    sawyer (0.5.4)
      addressable (~> 2.3.5)
      faraday (~> 0.8, < 0.10)
    tachikoma (4.0.3)
      json
      octokit (>= 2, < 3)
      rake
      safe_yaml
      thor
    thor (0.19.1)

PLATFORMS
  ruby

DEPENDENCIES
  bundler
  byebug
  rake
  snake!

bundler-1-6-0.txt

Installing sass-rails 4.0.1
/root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/installer.rb:309:in `install_in_parallel'Unfortunately, a fatal error has occurred. Please see the Bundler
troubleshooting documentation at http://bit.ly/bundler-issues. Thanks!
: undefined method `[]' for nil:NilClass (NoMethodError)
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/installer.rb:95:in `run'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/installer.rb:15:in `install'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/cli/install.rb:76:in `run'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/cli.rb:146:in `install'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/vendor/thor/command.rb:27:in `run'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/vendor/thor/invocation.rb:121:in `invoke_command'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/vendor/thor.rb:363:in `dispatch'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/vendor/thor/base.rb:440:in `start'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/cli.rb:9:in `start'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/bin/bundle:20:in `block in <top (required)>'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler/friendly_errors.rb:5:in `with_friendly_errors'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/bin/bundle:20:in `<top (required)>'
        from /root/.rbenv/versions/2.1.1/bin/bundle:23:in `load'
        from /root/.rbenv/versions/2.1.1/bin/bundle:23:in `<main>'
/root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/rake-10.1.1/lib/rake/file_utils.rb:54:in `block in create_shell_runner': Command failed with status (1): [bundle --gemfile Gemfile --no-deployment -...] (RuntimeError)
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/rake-10.1.1/lib/rake/file_utils.rb:45:in `call'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/rake-10.1.1/lib/rake/file_utils.rb:45:in `sh'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/tachikoma-4.0.3/lib/tachikoma/application.rb:76:in `block (2 levels) in bundle'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler.rb:234:in `block in with_clean_env'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler.rb:221:in `with_original_env'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/bundler-1.6.0/lib/bundler.rb:227:in `with_clean_env'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/tachikoma-4.0.3/lib/tachikoma/application.rb:71:in `block in bundle'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/tachikoma-4.0.3/lib/tachikoma/application.rb:70:in `chdir'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/tachikoma-4.0.3/lib/tachikoma/application.rb:70:in `bundle'
        from /code/github.com/sanemat/snake.tachikoma.io/lib/snake/cli.rb:86:in `snake_exec'
        from /code/github.com/sanemat/snake.tachikoma.io/lib/snake/cli.rb:18:in `tachikoma'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/thor-0.19.1/lib/thor/command.rb:27:in `run'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/thor-0.19.1/lib/thor/invocation.rb:126:in `invoke_command'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/thor-0.19.1/lib/thor.rb:359:in `dispatch'
        from /root/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/thor-0.19.1/lib/thor/base.rb:440:in `start'
        from bin/snake:6:in `<main>'

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 13.10
Release:        13.10
Codename:       saucy
# uname -a
Linux 6ef3f4558b91 3.11.0-12-generic #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

bundle --jobs=4 fails, bundle works fine.