bundle install outputs a Gemfile parsing error

[seekr]

[!] There was an error parsingGemfile`: xmlXPathCompOpEval: function hover not found . Bundler cannot continue.

from /Users/_/Dropbox/_dev/__/_**/Gemfile:11

-------------------------------------------

html = File.read("index.html")

puts InlineStyle.process(html, :stylesheets_paths => "/css")

-------------------------------------------

`