Bug of bundler

gistfile1.txt

Unfortunately, a fatal error has occurred. Please see the Bundler troubleshooting
documentation at http://bit.ly/bundler-issues. Thanks!
/var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/installer.rb:326:in `install_in_parallel': undefined method `[]' for nil:NilClass (NoMethodError)
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/installer.rb:95:in `run'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/installer.rb:15:in `install'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/cli.rb:257:in `install'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/vendor/thor/command.rb:27:in `run'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/vendor/thor/invocation.rb:120:in `invoke_command'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/vendor/thor.rb:363:in `dispatch'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/vendor/thor/base.rb:438:in `start'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/cli.rb:10:in `start'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/bin/bundle:22:in `block in <top (required)>'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/lib/bundler/friendly_errors.rb:5:in `with_friendly_errors'
	from /var/lib/gems/2.0.0/gems/bundler-1.5.1/bin/bundle:22:in `<top (required)>'
	from /usr/local/bin/bundle:23:in `load'
	from /usr/local/bin/bundle:23:in `<main>'
root@53bb6779d005:/mnt/api# bundle install