【发布时间】：2019-03-22 10:43:15
【问题描述】：
我是 Rails 新手。我按照 web of rails 上的教程进行操作。安装sqlite3 后，我尝试启动服务器，但我不能。终端显示这段代码
invitado@Home:~/blog$ bin/rails server
=> Booting Puma
=> Rails 5.2.2 application starting in development
=> Run `rails server -h` for more startup options
/usr/lib/ruby/vendor_ruby/rack/mime.rb:54: warning: already initialized constant Rack::Mime::MIME_TYPES
/var/lib/gems/2.3.0/gems/rack-2.0.6/lib/rack/mime.rb:49: warning: previous definition of MIME_TYPES was here
/usr/lib/ruby/vendor_ruby/rack/file.rb:15: warning: already initialized constant Rack::File::ALLOWED_VERBS
/var/lib/gems/2.3.0/gems/rack-2.0.6/lib/rack/file.rb:17: warning: previous definition of ALLOWED_VERBS was here
/usr/lib/ruby/vendor_ruby/rack/file.rb:16: warning: already initialized constant Rack::File::ALLOW_HEADER
/var/lib/gems/2.3.0/gems/rack-2.0.6/lib/rack/file.rb:18: warning: previous definition of ALLOW_HEADER was here
/usr/lib/ruby/vendor_ruby/rack/response.rb:23: warning: already initialized constant Rack::Response::CHUNKED
/var/lib/gems/2.3.0/gems/rack-2.0.6/lib/rack/response.rb:26: warning: previous definition of CHUNKED was here
Exiting
/var/lib/gems/2.3.0/gems/bootsnap-1.4.1/lib/bootsnap/load_path_cache/core_ext/active_support.rb:76:in `block in load_missing_constant': uninitialized constant Rack::Session::Abstract::Persisted (NameError)
from /var/lib/gems/2.3.0/gems/bootsnap-1.4.1/lib/bootsnap/load_path_cache/core_ext/active_support.rb:8:in without_bootsnap_cache
等等，有很多行。如果有人可以帮助我，我将不胜感激。谢谢！
【问题讨论】：
-
您的
bundle install是否顺利通过？另外，可能与this有关。
标签： ruby-on-rails ruby rubygems runtime-error puma