基于域名实现多语言时Devise路由报错问题排查

我想通过域名实现多语言功能，例如domain.fi.local对应芬兰语、domain.es.local对应西班牙语，且每个域名下均可切换至英语。为每个域名添加路由约束后，Devise功能出现失效问题：

• 将devise_for放在约束外可避免重复调用报错，但访问Devise路由（如登出）时仍报错；
• 尝试在约束内添加devise_for :users, skip: :all，问题依旧。

原始routes.rb代码 #

Rails.application.routes.draw do
  devise_for :users

  constraints(host: "domain.fi.local") do
    scope "(:locale)", locale: /fi|en/ do
      resources :users do
        resource :profile, only: [:show, :edit, :update]
      end
      resources :trips
    end
  end

  constraints(host: "domain.es.local") do
    scope "(:locale)", locale: /es|en/ do
      resources :users do
        resource :profile, only: [:show, :edit, :update]
      end
      resources :trips
    end
  end

  # 通用 fallback 路由（默认英语）
  scope "(:locale)", locale: /en|fi|es/ do
    resources :users do
      resource :profile, only: [:show, :edit, :update]
    end
    resources :trips
  end

  # 健康检查
  get "up" => "rails/health#show", as: :rails_health_check

  # 唯一根路径避免冲突
  root "trips#index"
end

修改后的routes.rb代码 #

Rails.application.routes.draw do
  # 全局定义Devise路由（约束外）
  devise_for :users

  constraints(host: "domain.fi.local") do
    scope "(:locale)", locale: /fi|en/ do
      devise_for :users, skip: :all  # 避免约束内生成重复路由
      resources :users do
        resource :profile, only: [:show, :edit, :update]
      end
      resources :trips
    end
  end

  constraints(host: "domain.es.local") do
    scope "(:locale)", locale: /es|en/ do
      devise_for :users, skip: :all  # 避免约束内生成重复路由
      resources :users do
        resource :profile, only: [:show, :edit, :update]
      end
      resources :trips
    end
  end

  # 通用 fallback 路由（默认英语）
  scope "(:locale)", locale: /en|fi|es/ do
    devise_for :users, skip: :all  # 避免生成重复路由
    resources :users do
      resource :profile, only: [:show, :edit, :update]
    end
    resources :trips
  end

  # 健康检查
  get "up" => "rails/health#show", as: :rails_health_check

  # 唯一根路径避免冲突
  root "trips#index"
end

内容的提问来源于stack exchange，提问作者narovi