在我的 foreman/katello 安装中出现以下错误消息：
无法启动 Web 应用程序
(RuntimeError)
/opt/theforeman/tfm/root/usr/share/gems/gems/ffi-1.4.0/lib/ffi/library.rb:253:in `attach'
/opt/theforeman/tfm/root/usr/share/gems/gems/ffi-1.4.0/lib/ffi/library.rb:253:in `attach_function'
/opt/theforeman/tfm/root/usr/share/gems/gems/gssapi-1.2.0/lib/gssapi/lib_gssapi.rb:13:in `<module:LibGSSAPI>'
/opt/theforeman/tfm/root/usr/share/gems/gems/gssapi-1.2.0/lib/gssapi/lib_gssapi.rb:8:in `<module:GSSAPI>'
/opt/theforeman/tfm/root/usr/share/gems/gems/gssapi-1.2.0/lib/gssapi/lib_gssapi.rb:7:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/gssapi-1.2.0/lib/gssapi.rb:17:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/net-ssh-krb-0.4.0/lib/net/ssh/authentication/methods/gssapi_with_mic.rb:3:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/net-ssh-krb-0.4.0/lib/net/ssh/kerberos.rb:7:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/net-ssh-krb-0.4.0/lib/net/ssh/krb.rb:1:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `rescue in require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:39:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman_remote_execution_core-1.1.0/lib/foreman_remote_execution_core/script_runner.rb:5:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman_remote_execution_core-1.1.0/lib/foreman_remote_execution_core.rb:35:in `<module:ForemanRemoteExecutionCore>'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman_remote_execution_core-1.1.0/lib/foreman_remote_execution_core.rb:3:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman_remote_execution-1.4.5/lib/foreman_remote_execution/engine.rb:1:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/foreman_remote_execution-1.4.5/lib/foreman_remote_execution.rb:4:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:133:in `rescue in require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:39:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/polyglot-0.3.5/lib/polyglot.rb:65:in `require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext/runtime.rb:41:in `block in system_require'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext/runtime.rb:37:in `each'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext/runtime.rb:37:in `system_require'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext.rb:19:in `block in system_require'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext.rb:14:in `each'
/opt/theforeman/tfm/root/usr/share/gems/gems/bundler_ext-0.4.1/lib/bundler_ext.rb:14:in `system_require'
/usr/share/foreman/config/application.rb:17:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/usr/share/foreman/config/environment.rb:2:in `<top (required)>'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
/opt/rh/rh-ruby24/root/usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
config.ru:3:in `block in <main>'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/rack-2.0.3/lib/rack/builder.rb:55:in `instance_eval'
/opt/theforeman/tfm-ror51/root/usr/share/gems/gems/rack-2.0.3/lib/rack/builder.rb:55:in `initialize'
config.ru:1:in `new'
config.ru:1:in `<main>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:112:in `eval'
/usr/share/passenger/helper-scripts/rack-preloader.rb:112:in `preload_app'
/usr/share/passenger/helper-scripts/rack-preloader.rb:158:in `<module:App>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:29:in `<module:PhusionPassenger>'
/usr/share/passenger/helper-scripts/rack-preloader.rb:28:in `<main>'
Error ID
9e2b7253
显然，应用程序无法运行。但是，所有 katello/foreman 服务均正常运行。
/var/log/foreman/production.log没有错误。
foreman-proxy 日志的信息更少（空），tomcat 日志什么都没有显示！
那么，什么失败了？