在我刚刚从4.1升级rails并将ruby从2.0升级到2.1之后，当我尝试启动rails时，我遇到了几个加载问题。我的很多宝石都会抛出这样的错误：
/Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require': cannot load such file -- jwt (LoadError)
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/oauth2-1.0.0/lib/oauth2/strategy/assertion.rb:1:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/oauth2-1.0.0/lib/oauth2.rb:8:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/omniauth-oauth2-1.2.0/lib/omniauth/strategies/oauth2.rb:1:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/omniauth-facebook-2.0.0/lib/omniauth/strategies/facebook.rb:1:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/omniauth-facebook-2.0.0/lib/omniauth/facebook.rb:2:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in `load_dependency'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/omniauth-facebook-2.0.0/lib/omniauth-facebook.rb:1:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:76:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:72:in `each'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:72:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:61:in `each'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:61:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler.rb:133:in `require'
from /Users/nk/Programmering/au/au/config/application.rb:4:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:146:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:146:in `require_application_and_environment!'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:68:in `console'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands.rb:17:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
我的宝石文件如下所示：
source 'https://rubygems.org'
# Rake and rails
gem 'rake', '10.3.2'
gem 'rails', '4.1.6'
gem 'protected_attributes'
gem 'rails-observers'
gem 'actionpack-page_caching'
gem 'actionpack-action_caching'
gem 'activerecord-deprecated_finders'
# Databases and caching
gem 'pg', '0.17.1'
gem 'apartment', '0.25.2'
gem 'redis', '~> 3.1.0'
gem 'foreigner', '1.6.1'
gem 'geocoder', '1.2.5'
gem 'dalli', '2.7.2'
gem 'hstore_accessor', '~> 0.6.0'
# Files and processing
gem 'fog', '~> 1.24.0'
gem 'rmagick', '~> 2.13.2', require: 'RMagick'
gem 'carrierwave', '~> 0.10.0'
gem 'carrierwave-meta', '~> 0.0.5'
gem 'rubyzip', '~> 1.1.2'
gem 'sitemap_generator', '~> 5.0.1'
gem 'rubyXL', '~> 3.2.3'
# Model layer
gem 'squeel', '~> 1.2.1'
gem 'ransack', '~> 1.4.0'
gem 'state_machine', '~> 1.2.0'
gem 'active_attr', '0.8.4'
gem 'omniauth-facebook', '2.0.0'
gem 'omniauth-identity', '1.1.1'
gem 'bcrypt-ruby', '~> 3.1.2', require: 'bcrypt'
gem 'redis-objects', '~> 1.0.0'
gem 'leaderboard', '~> 3.7.0'
现在，如果我发表评论omniauth-facebook，那么我只需为bcrupt获取以下内容：
/Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:76:in `require': cannot load such file -- bcrypt (LoadError)
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:72:in `each'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:72:in `block in require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:61:in `each'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler/runtime.rb:61:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@global/gems/bundler-1.7.3/lib/bundler.rb:133:in `require'
from /Users/nk/Programmering/au/au/config/application.rb:4:in `<top (required)>'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:146:in `require'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:146:in `require_application_and_environment!'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:68:in `console'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
from /Users/nk/.rvm/gems/ruby-2.1.3@au_rails4/gems/railties-4.1.6/lib/rails/commands.rb:17:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
就这样继续下去。为什么我的一些宝石会突然造成这种情况呢？
答案 0 :(得分：7)
您当地的ruby安装必定存在问题。
如果您使用的是rvm gemset，请在您的gemset上运行rvm pristine。
如果您不使用gemset，请运行gem pristine --all
答案 1 :(得分：3)
对我来说，感觉就像你在没有捆绑器的情况下全局安装了一些宝石而没有将宝石添加到Gemfile。如果没有Gemfile.lock，则很难说，但jwt Gem不在您的Gemfile中。
我会尝试将缺少的宝石添加到您的Gemfile中，再次运行bundle install。
答案 2 :(得分：1)
您是否尝试过使用bundler将gems重新安装到应用程序中的位置？
bundle install --path vendor/bundle
另外：如果这没有帮助，我会尝试在rvm中删除gemset并再次尝试bundle / rails c。
答案 3 :(得分：1)
首先，我希望您正在运行“捆绑exec rails c”而不仅仅是“rails c”以确保您从正确的位置加载宝石。
如果是这种情况，请尝试运行“bundle show bcrypt”并检查路径，它应该以
开头"/Users/nk/.rvm/gems/ruby-2.1.3/"
如果没有，通过删除Gemfile.lock来重置bundler并再次运行bundle install或类似的帮助。
答案 4 :(得分：0)
迁移后你运行了bundle update吗？如果没有，请运行bundle update并尝试。在此之前删除Gemfile.lock文件
答案 5 :(得分：0)
删除 Gemfile.lock 文件并尝试再次运行捆绑更新，然后再运行捆绑安装。我希望它适合你。