There appears to be a bug in the ruby-runtime plugin when attempting to extract hpi files installed on a windows path with containing spaces. The apparent behavior is that the ruby-runtime dependency will install successfully but any ruby plugins listing it as a dependency will fail upon installation with the following error message:

Caused by: java.lang.Exception: unable to locate gem bundle for ruby-plugin at C:\Program%20Files%20(x86)\Jenkins\plugins\ruby-plugin\WEB-INF\classes\vendor\gems
at ruby.RubyPlugin.initRubyLoadPaths(RubyPlugin.java:229)
at ruby.RubyPlugin.start(RubyPlugin.java:162)
at hudson.ClassicPluginStrategy.startPlugin(ClassicPluginStrategy.java:416)
at hudson.ClassicPluginStrategy.load(ClassicPluginStrategy.java:405)
... 8 more