title: Errno::EPERM: Operation not permitted @ dir_s_rmdir
body: <p>I'm getting this error when running bundle install: </p>
  
  <pre><code>Errno::EPERM: Operation not permitted @ dir_s_rmdir - /home/rbtlong/.bundle/cache/compact_index/rubygems.org.443.29b0360b937aa4d161703e6160654e47/versions
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/compact_index_client/lib/compact_index_client/updater.rb:50:in `unlink'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/compact_index_client/lib/compact_index_client/updater.rb:50:in `delete'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/compact_index_client/lib/compact_index_client/updater.rb:50:in `update'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/compact_index_client/lib/compact_index_client.rb:64:in `update'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/compact_index_client/lib/compact_index_client.rb:55:in `update_and_parse_checksums!'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/fetcher/compact_index.rb:65:in `available?'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/fetcher/compact_index.rb:15:in `call'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/fetcher/compact_index.rb:15:in `block in compact_index_request'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/fetcher.rb:154:in `use_api'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:331:in `block in api_fetchers'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:331:in `select'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:331:in `api_fetchers'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:336:in `block in remote_specs'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/index.rb:10:in `build'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:335:in `remote_specs'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/source/rubygems.rb:82:in `specs'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/lazy_specification.rb:56:in `__materialize__'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/spec_set.rb:91:in `block in materialize'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/spec_set.rb:88:in `map!'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/spec_set.rb:88:in `materialize'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/definition.rb:140:in `specs'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/definition.rb:129:in `resolve_remotely!'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/installer.rb:195:in `resolve_if_need'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/installer.rb:70:in `run'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/installer.rb:22:in `install'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/cli/install.rb:102:in `run'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/cli.rb:175:in `install'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/thor/lib/thor.rb:359:in `dispatch'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/vendor/thor/lib/thor/base.rb:440:in `start'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/cli.rb:11:in `start'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/exe/bundle:27:in `block in &lt;top (required)&gt;'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/lib/bundler/friendly_errors.rb:98:in `with_friendly_errors'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/gems/bundler-1.12.3/exe/bundle:19:in `&lt;top (required)&gt;'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/bin/bundle:23:in `load'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/bin/bundle:23:in `&lt;main&gt;'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/bin/ruby_executable_hooks:15:in `eval'
  /home/rbtlong/.rvm/gems/ruby-2.2.3/bin/ruby_executable_hooks:15:in `&lt;main&gt;'
  </code></pre>
  
  <p>Environment:</p>
  
  <pre><code>Bundler 1.12.3
  Rubygems 2.4.8
  Ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-linux]
  GEM_HOME /home/rbtlong/.rvm/gems/ruby-2.2.3
  GEM_PATH /home/rbtlong/.rvm/gems/ruby-2.2.3:/home/rbtlong/.rvm/gems/ruby-2.2.3@global
  RVM 1.27.0 (latest)
  Git 2.5.0
  rubygems-bundler (1.4.4)
  </code></pre>
  
  <p>Bundler Settings:</p>
  
  <pre><code>orig_path
  Set via BUNDLE_ORIG_PATH: "/home/rbtlong/.rvm/gems/ruby-2.2.3/bin:/home/rbtlong/.rvm/gems/ruby-2.2.3@global/bin:/home/rbtlong/.rvm/rubies/ruby-2.2.3/bin:/home/rbtlong/.rvm/bin:/home/rbtlong/.dnx/runtimes/dnx-mono.1.0.0-rc1-update1/bin:/home/rbtlong/.dnx/bin:/usr/local/heroku/bin:/home/rbtlong/.rbenv/plugins/ruby-build/bin:/home/rbtlong/.rbenv/shims:/home/rbtlong/.rbenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
  orig_gem_path
  Set via BUNDLE_ORIG_GEM_PATH: "/home/rbtlong/.rvm/gems/ruby-2.2.3:/home/rbtlong/.rvm/gems/ruby-2.2.3@global"
  </code></pre>