加载错误：无法加载文件——rspec/core/rake_task。

当我执行 rake 命令时，我收到了这个错误。

AllenLins-MacBook-Pro:geoblacklight allenlin$ rake -t
Resolving dependencies...
You must `gem install bundler` and `bundle install` to run rake tasks
rake aborted!
LoadError: cannot load such file -- rspec/core/rake_task
/Users/allenlin/Documents/USpatial/geoblacklight/Rakefile:12:in `require'
/Users/allenlin/Documents/USpatial/geoblacklight/Rakefile:12:in `'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/rake_module.rb:28:in `load'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/rake_module.rb:28:in `load_rakefile'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:689:in `raw_load_rakefile'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:94:in `block in load_rakefile'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:176:in `standard_exception_handling'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:93:in `load_rakefile'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:77:in `block in run'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:176:in `standard_exception_handling'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:75:in `run'
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/rake-10.4.2/bin/rake:33:in `'
/Users/allenlin/.rbenv/versions/2.2.2/bin/rake:23:in `load'
/Users/allenlin/.rbenv/versions/2.2.2/bin/rake:23:in `

然而，我已经执行了\'gem install bundler\'和\'bundle install\'命令，rspec/core/rake_task实际上已经存在，并被显示为

AllenLins-MacBook-Pro:geoblacklight allenlin$ gem which rspec/core/rake_task
/Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/rspec-core-3.0.4/lib/rspec/core/rake_task.rb

我在这里迷失了方向。非常感谢任何帮助！我附上了 Gemfile 文件：

source 'https://rubygems.org'
# Specify your gem's dependencies in geoblacklight.gemspec
gemspec
# If we don't specify 2.11.0 we'll end up with sprockets 2.12.0 in the main
# Gemfile.lock but since sass-rails gets generated (rails new) into the test app
# it'll want sprockets 2.11.0 and we'll have a conflict
gem 'sprockets', '2.11.0'
# If we don't specify 3.2.15 we'll end up with sass 3.3.2 in the main
# Gemfile.lock but since sass-rails gets generated (rails new) into the test app
# it'll want sass 3.2.0 and we'll have a conflict
gem 'sass', '~> 3.2.0'
gem 'bootstrap-sass', ">= 3.2"
group :test do
  # Peg simplecov to < 0.8 until this is resolved: # https://github.com/colszowka/simplecov/issues/281 gem 'simplecov', '~> 0.7.1', require: false
  gem 'coveralls', require: false
end

更新

如果有用的话，附上我的 gem 环境信息。

RubyGems Environment:
  - RUBYGEMS VERSION: 2.4.5
  - RUBY VERSION: 2.2.2 (2015-04-13 patchlevel 95) [x86_64-darwin14]
  - INSTALLATION DIRECTORY: /Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0
  - RUBY EXECUTABLE: /Users/allenlin/.rbenv/versions/2.2.2/bin/ruby
  - EXECUTABLE DIRECTORY: /Users/allenlin/.rbenv/versions/2.2.2/bin
  - SPEC CACHE DIRECTORY: /Users/allenlin/.gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /Users/allenlin/.rbenv/versions/2.2.2/etc
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-darwin-14
  - GEM PATHS:
     - /Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0
     - /Users/allenlin/.gem/ruby/2.2.0
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - https://rubygems.org/
  - SHELL PATH:
     - /Users/allenlin/.rbenv/versions/2.2.2/bin
     - /usr/local/Cellar/rbenv/0.4.0/libexec
     - /Users/allenlin/.rbenv/shims
     - /Applications/Postgres.app/Contents/Versions/9.3/bin
     - /Library/Frameworks/Python.framework/Versions/2.7/bin
     - /Users/allenlin/Library/Enthought/Canopy_64bit/User/bin
     - /Users/allenlin/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.6/bin
     - /Users/allenlin/gradle-1.12/bin
     - /usr/local/bin
     - /Users/allenlin/apache-maven/apache-maven-3.1.1/bin
     - /usr/local/bin
     - /usr/bin
     - /bin
     - /usr/sbin
     - /sbin
     - /opt/X11/bin
     - /usr/local/git/bin
     - /usr/texbin