麻烦“激活”宝石版

Question

我正在铁道上上课程并且对宝石有些麻烦。

当我在新的rails项目上运行rspec时，我收到此错误：

/Users/mme/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/bundler-1.11.2/lib/bundler/runtime.rb:34:in `block in setup': 
You have already activated poltergeist 1.9.0, but your Gemfile requires poltergeist 1.6.0. 
Prepending `bundle exec` to your command may solve this. (Gem::LoadError)

根据How to switch between different version of gem installed?，我应该可以使用bundle exec [gem]

$ bundle exec poltergeist
bundler: command not found: poltergeist
Install missing gem executables with `bundle install`

这没有意义 - 我之前使用过poltergeist：

$ bundle install | grep poltergeist
Using poltergeist 1.6.0

有没有人对如何调和这种情况有一些建议？

Answer 1

尝试：

bundle exec rspec

错误表明＆＃34;将bundle exec添加到您的命令＆＃34; - 字面意思是在bundle exec命令之前添加rspec。