我仅在单个 CentOS 6 VM 映像上收到捆绑安装错误，但不知道为什么 extconf.rb 无法仅通过 bundler正常运行。
我在 RedCloth 和 bcrypt-ruby 中都看到了这一点，而 gem_make.out 只包含一行：
/usr/local/rvm/rubies/ree-1.8.7-2012.02/bin/ruby extconf.rb
我能够通过运行安装 RedCloth gem install RedCloth -v '4.2.8'，但随后遇到了与bcrypt-ruby相同的问题。
我尝试运行cd /usr/local/rvm/gems/ree-1.8.7-2012.02@rujoisxk/gems/bcrypt-ruby-2.1.4 && ruby ext/mri/extconf.rb，它成功创建了一个 Makefile。我想知道为什么会这样
$ bundle install --verbose
[...SNIP...]
Fetching from: http://rubygems.org/quick/Marshal.4.8/bcrypt-ruby-2.1.4.gemspec.rz
HTTP Redirection
Fetching from: http://production.cf.rubygems.org/quick/Marshal.4.8/bcrypt-ruby-2.1.4.gemspec.rz
HTTP Success
Installing bcrypt-ruby (2.1.4) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/usr/local/rvm/rubies/ree-1.8.7-2012.02/bin/ruby extconf.rb
Gem files will remain installed in /usr/local/rvm/gems/ree-1.8.7-2012.02@rujoisxk/gems/bcrypt-ruby-2.1.4 for inspection.
Results logged to /usr/local/rvm/gems/ree-1.8.7-2012.02@rujoisxk/gems/bcrypt-ruby-2.1.4/ext/mri/gem_make.out
Extension: ext/mri/extconf.rb
/usr/local/rvm/rubies/ree-1.8.7-2012.02/lib/ruby/site_ruby/1.8/rubygems/installer.rb:557:in `build_extensions'
/usr/local/rvm/rubies/ree-1.8.7-2012.02/lib/ruby/site_ruby/1.8/rubygems/installer.rb:509:in `each'
/usr/local/rvm/rubies/ree-1.8.7-2012.02/lib/ruby/site_ruby/1.8/rubygems/installer.rb:509:in `build_extensions'
/usr/local/rvm/rubies/ree-1.8.7-2012.02/lib/ruby/site_ruby/1.8/rubygems/installer.rb:180:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/source.rb:90:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/rubygems_integration.rb:82:in `preserve_paths'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/source.rb:89:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:106:in `install_gem_from_spec'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/rubygems_integration.rb:97:in `with_build_args'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:105:in `install_gem_from_spec'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:89:in `run'
(__FORWARDABLE__):3:in `each'
(__FORWARDABLE__):3:in `__send__'
(__FORWARDABLE__):3:in `each'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:88:in `run'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:14:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/cli.rb:230:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/task.rb:27:in `send'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/task.rb:27:in `run'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/invocation.rb:120:in `invoke_task'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor.rb:275:in `dispatch'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/base.rb:408:in `start'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/bin/bundle:14
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/friendly_errors.rb:4:in `with_friendly_errors'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/bin/bundle:14
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/bin/bundle:23:in `load'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/bin/bundle:23
An error occurred while installing bcrypt-ruby (2.1.4), and Bundler cannot continue.
Make sure that `gem install bcrypt-ruby -v '2.1.4'` succeeds before bundling.
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:128:in `install_gem_from_spec'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:89:in `run'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:88:in `run'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/installer.rb:14:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/cli.rb:230:in `install'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/task.rb:27:in `send'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/task.rb:27:in `run'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/invocation.rb:120:in `invoke_task'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor.rb:275:in `dispatch'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/vendor/thor/base.rb:408:in `start'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/bin/bundle:14
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/lib/bundler/friendly_errors.rb:4:in `with_friendly_errors'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/gems/bundler-1.2.0/bin/bundle:14
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/bin/bundle:23:in `load'
/usr/local/rvm/gems/ree-1.8.7-2012.02@global/bin/bundle:23