Ruby on Rails：無法加載rack / handler /

Question

昨晚我有一個完全工作的Rails服務器。 但是，在今天早上訪問我的電腦時，我發現它已經崩潰了。 我啟動了備份，然后SSH連接到我的遠程服務器，並嘗試重新啟動服務器進程，首先查詢：

rails server -h

結果導致：

/usr/local/lib/site_ruby/2.3.0/rubygems.rb:270:in `find_spec_for_exe': can't find gem railties (>= 0.a) (Gem::GemNotFoundException)
from /usr/local/lib/site_ruby/2.3.0/rubygems.rb:298:in `activate_bin_path'
from /usr/local/bin/rails:22:in `<main>'

然后我嘗試了一個bundle install ，它拋出了以下錯誤：

    enter code here/usr/local/lib/site_ruby/2.3.0/rubygems.rb:270:in `find_spec_for_exe': can't find gem bundler (>= 0.a) (Gem::GemNotFoundException)
from /usr/local/lib/site_ruby/2.3.0/rubygems.rb:298:in `activate_bin_path'
from /usr/local/bin/bundle:22:in `<main>'

然后我用rvm use ruby-2.3.1@rails5.0 --create重新安裝Rails rvm use ruby-2.3.1@rails5.0 --create后跟gem install rails 。 rails -v now報告：

Rails 5.0.1

但是，當我嘗試啟動服務器進程（ rails server -p 80 - b 139.162.246.138 ）時，我得到：

Exiting
/home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/rack-2.0.1/lib/rack/handler.rb:74:in `require': cannot load such file -- rack/handler/- (LoadError)
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/rack-2.0.1/lib/rack/handler.rb:74:in `try_require'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/rack-2.0.1/lib/rack/handler.rb:16:in `get'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/rack-2.0.1/lib/rack/server.rb:300:in `server'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/server.rb:112:in `print_boot_information'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/server.rb:73:in `start'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
    from /home/peter/.rvm/gems/ruby-2.3.1@rails5.0/gems/railties-5.0.1/lib/rails/commands.rb:18:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

我嘗試卸載並重新安裝ruby和rails，並運行新的bundle install 。 沒有得到基本相同的錯誤：

    /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/activesupport-5.0.1/lib/active_support/xml_mini.rb:51: warning: constant ::Fixnum is deprecated
/home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/activesupport-5.0.1/lib/active_support/xml_mini.rb:52: warning: constant ::Bignum is deprecated
Exiting
/home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/rack-2.0.1/lib/rack/handler.rb:74:in `require': cannot load such file -- rack/handler/- (LoadError)
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/rack-2.0.1/lib/rack/handler.rb:74:in `try_require'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/rack-2.0.1/lib/rack/handler.rb:16:in `get'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/rack-2.0.1/lib/rack/server.rb:300:in `server'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/server.rb:112:in `print_boot_information'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/server.rb:73:in `start'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
    from /home/peter/.rvm/gems/ruby-2.4.0-rc1/gems/railties-5.0.1/lib/rails/commands.rb:18:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

我還嘗試完全卸載rails和railties：

gem uninstall rails -v 5.0.1
gem uninstall railties -v 5.0.1
gem install rails -v 5.0.1
gen install railties -v 5.0.1

同樣的錯誤。

嘗試使用以下命令查找問題：

sudo grep -rnw './' -e "/var/lib/gems/2.3.0/"

從源目錄輸出到控制台。

嘗試訪問錯誤消息中列出的目錄會導致：

cd /var/lib/gems/
-bash: /home/peter/.rvm/scripts/initialize: No such file or directory 
-bash: /home/peter/.rvm/scripts/hook: No such file or directory

運行sudo gem uninstall --all以刪除所有gems導致：

You have requested to uninstall the gem:
    actioncable-5.0.1

rails-5.0.1 depends on actioncable (= 5.0.1)
If you remove this gem, these dependencies will not be met.
Continue with Uninstall? [yN]  ERROR:  While executing gem ... (Gem::DependencyRemovalException)
    Uninstallation aborted due to dependent gem(s)

雖然在運行命令之前刪除rails-5.0.1 gem修復了這個...但是，運行這個應該刪除所有 gem的命令之后， rails -v現在輸出：

Rails 4.2.7.1

並且運行gem uninstall rails-4.2.7.1不會刪除此版本。

gem uninstall -v rails-4.2.7.1導致：

ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
Illformed requirement ["rails-4.2.7.1"]

更新：最終設法刪除rails和ruby。 重新安裝它們。 同樣的問題。

嘗試創建一個重新啟動項目和新項目完全相同的事情。

Answer 1

完成所有工作后，解決方案很簡單。 我在打字：

rails server -p 80 - b 139.162.246.138

代替：

rails server -p 80 -b 139.162.246.138

Answer 2

你使用=> rbenv安裝寶石后重新開始嗎？ 如果沒有檢查=> gemfile以確保你有匹配的ruby版本以及你的=> gemfile.lock（在你工作的目錄中）

Answer 3

這個故事的寓意是，如果你在調用rails服務器時在命令行上亂碼，你會得到：

bootsnap-1.3.2/lib/bootsnap/load_path_cache/
core_ext/kernel_require.rb:32:in `require': cannot 
load such file -- rack/handler/--some-wrong-option (LoadError)  

這是一個小曖昧。 並不是說bootsnap不能加載機架，而是它無法加載機架“一些錯誤的選項”處理程序，因為你的選擇是錯誤的，可能是一個錯字。