为什么Elixir Guardian（DB）在查找令牌时遇到问题？

我很难理解guardian是如何工作或处理错误的，所以在本例中，我只是尝试注销并在控制台上获取错误

代码：

def delete（conn，_参数）do
{：好的，claims}=Guardian.Plug.claims（conn）
康涅狄格州
|>Guardian.Plug.current_令牌
|>卫报，撤销！（索赔）
康涅狄格州
|>render（“delete.json”）
结束

不知何故，即使删除了会话，也找不到令牌，用户已注销。 我调试代码时遇到问题。 如何更好地查找错误或调试代码

错误消息：

[error] #PID<0.2061.0> running PhoenixExample.Endpoint terminated
Server: 127.0.0.1:4000 (http)
Request: DELETE /api/v1/sessions
** (exit) an exception was raised:
    ** (Ecto.StaleEntryError) attempted to delete a stale struct:

%GuardianDb.Token{__meta__: #Ecto.Schema.Metadata<:loaded, "guardian_tokens">, aud: "User:96900", claims: %{"aud" => "User:96900", "exp" => 1474754356, "iat" => 1472162356, "iss" => "PhoenixExample", "jti" => "8947def5-ec3e-46e1-866d-2a1e9e16fd1f", "pem" => %{}, "sub" => "User:96900", "typ" => "token"}, exp: 1474754356, inserted_at: #Ecto.DateTime<2016-08-25 21:59:16>, iss: "PhoenixExample", jti: "8947def5-ec3e-46e1-866d-2a1e9e16fd1f", jwt: "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJVc2VyOjk2OTAwIiwiZXhwIjoxNDc0NzU0MzU2LCJpYXQiOjE0NzIxNjIzNTYsImlzcyI6IkNhbGx5YWNvcmUiLCJqdGkiOiI4OTQ3ZGVmNS1lYzNlLTQ2ZTEtODY2ZC0yYTFlOWUxNmZkMWYiLCJwZW0iOnt9LCJzdWIiOiJVc2VyOjk2OTAwIiwidHlwIjoidG9rZW4ifQ.BTYn7wjPlosztNmy3DKeRExzwBOiUG_ZLBJqUzUinDIpEl0xvUnb3EzYM7VaBpIT__JtVfZ0t7XET9D0LK0eMg", sub: "User:96900", typ: "token", updated_at: #Ecto.DateTime<2016-08-25 21:59:16>}

        (ecto) lib/ecto/repo/schema.ex:397: Ecto.Repo.Schema.apply/4
        (ecto) lib/ecto/repo/schema.ex:341: anonymous fn/9 in Ecto.Repo.Schema.do_delete/4
        lib/guardian_db.ex:98: GuardianDb.on_revoke/2
        (guardian) lib/guardian.ex:131: Guardian.revoke!/3
        (phoenixexample) web/controllers/api/v1/session_controller.ex:30: PhoenixExample.SessionController.delete/2
        (phoenixexample) web/controllers/api/v1/session_controller.ex:1: PhoenixExample.SessionController.action/2
        (phoenixexample) web/controllers/api/v1/session_controller.ex:1: PhoenixExample.SessionController.phoenix_controller_pipeline/2
        (phoenixexample) lib/phoenixexample/endpoint.ex:1: PhoenixExample.Endpoint.instrument/4
        (phoenixexample) lib/phoenix/router.ex:261: PhoenixExample.Router.dispatch/2
        (phoenixexample) web/router.ex:1: PhoenixExample.Router.do_call/2
        (phoenixexample) lib/phoenixexample/endpoint.ex:1: PhoenixExample.Endpoint.phoenix_pipeline/1
        (phoenixexample) lib/plug/debugger.ex:122: PhoenixExample.Endpoint."call (overridable 3)"/2
        (phoenixexample) lib/phoenixexample/endpoint.ex:1: PhoenixExample.Endpoint.call/2
        (plug) lib/plug/adapters/cowboy/handler.ex:15: Plug.Adapters.Cowboy.Handler.upgrade/4
        (cowboy) src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4

[错误]#运行Phoenix示例的PID。终结点已终止
服务器：127.0.0.1:4000（http）
请求：删除/api/v1/sessions
**（退出）引发了一个异常：
**（Exto.StaleEntryError）试图删除陈旧结构：
%GuardianDb.Token{uuuuu meta}元数据，aud:“用户：96900”，声明：%{“aud”=>“用户：96900”，“exp”=>1474754356，“iat”=>1472162356，“iss”=>“PhoenixExample”，“jti”=>“8947def5-ec3e-46e1-866d-2ae9e16fd1f”，“pem”=>“用户：96900”，“typ”=>“exp”，exp:“插入时间：”phoenixe:“phoenixe:”，jti:“8947def5-ec3e-46e1-866d-2a1e9e16fd1f”，jwt：2.2.2.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6.6分：用户：96900”，类型：“令牌”，更新地址为：#exto.DateTime}
（exto）lib/exto/repo/schema.ex:397:exto.repo.schema.apply/4
（exto）lib/exto/repo/schema.ex:341:exto.repo.schema.do_delete/4中的匿名fn/9
lib/guardian_db.ex:98:GuardianDb.on_revoke/2
（监护人）lib/guardian.ex:131:guardian.revoke！/3
（phoenixexample）web/controllers/api/v1/session_controller.ex:30:phoenixexample.SessionController.delete/2
（phoenixexample）web/controllers/api/v1/session_controller.ex:1:phoenixexample.SessionController.action/2
（phoenix示例）web/controllers/api/v1/session\u controller.ex:1:phoenix示例.SessionController.phoenix\u controller\u管道/2
（phoenixexample）lib/phoenixexample/endpoint.ex:1:phoenixexample.endpoint.instrument/4
（phoenixexample）lib/phoenix/router.ex:261:phoenixexample.router.dispatch/2
（phoenixexample）web/router.ex1:phoenixexample.router.do_call/2
（phoenixexample）lib/phoenixexample/endpoint.ex:1:phoenixexample.endpoint.phoenix_管道/1
（phoenixexample）lib/plug/debugger.ex:122:phoenixexample.Endpoint.“调用（可重写3）”/2
（phoenixexample）lib/phoenixexample/endpoint.ex:1:phoenixexample.endpoint.call/2
（plug）lib/plug/adapters/cowboy/handler.ex:15:plug.adapters.cowboy.handler.upgrade/4
（cowboy）src/cowboy_protocol.erl:442:：cowboy_protocol.execute/4

控制室（已检查）

%Plug.Conn{adapter:{Plug.Adapters.Cowboy.Conn，：…}，赋值：%{}，
发送前：[函数，
#功能]，
body_参数：%{}，cookies:%Plug.Conn.Unfetched{aspect:：cookies}，
暂停：false，主机：“127.0.0.1”，方法：“删除”，所有者：#PID，
参数：%{}，路径信息：[“api”、“v1”、“会话”]，
对等：{127,0,0,1}，63006}，端口：4000，
私有：%%{PhoenixExample.Router=>{[]，%%{}}，
：guardian\u default\u claims=>{：好，
%{“aud”=>“User:96900”，“exp”=>1474754356，“iat”=>1472162356，
“iss”=>“Phoenix示例”，“jti”=>“8947def5-ec3e-46e1-866d-2a1e9e16fd1f”，
“pem”=>%{}，“sub”=>“用户：96900”，“类型”=>“令牌”}，
：guardian_default_jwt=>“Eyjhdwqioijvc2vyyyyyyyyyyyyyyyyyyyuxNdc0nzu2cjyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy，
：guardian_default_resource=>%PhoenixExample.User{{{uuuuu meta}:#exto.Schema.Metadata，
账户：无，地址：无，批准：假，城市：无，国家：无，
描述：无，电子邮件：“radosch@me.com",
加密密码：$2b$12$E8AOMRI6PVHLIUMENHMSOFCR8TRK4.HYaCSGQvrobgTYkWBdcV7m“，
名字：nil，guid:nil，id:96900，
插入位置：#exto.DateTime，是否提供程序：false，
姓氏：nil，密码：nil，邮政编码：nil，标签：nil，
更新地址：#exto.DateTime，用户名：“radosch”}，
：phoenix_action=>：删除，
：phoenix_controller=>PhoenixExample.SessionController，
：phoenix_endpoint=>PhoenixExample.endpoint，：phoenix_format=>“json”，
：phoenix_layout=>{PhoenixExample.LayoutView，：app}，
：phoenix_管道=>[：api]，
：phoenix_route=>#函数，
：phoenix_路由器=>phoenix示例路由器，
：phoenix_view=>PhoenixExample.SessionView，
：plug_session_fetch=>#Function}，
查询参数：%{}，查询字符串：，远程ip:{127,0,0,1}，
请求cookies:%Plug.Conn.Unfetched{aspect:：cookies}，
请求头：[{“主机”，“127.0.0.1:4000”}，{“内容长度”，“0”}，
{“连接”、“保持活动状态”}、{“接受”、“*/*”}、，
{“用户代理”，“CallYa/1 CFNetwork/808.0.1 Darwin/16.0.0”}，
{“接受语言”，“德奇”}，
{“授权”，
2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2.持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持持者的人的人的人的人的人的人的人的人的人的人，2.2.2.2.2.2.2.2“}，
{“接受编码”，“gzip，deflate”}]，请求路径：“/api/v1/sessions”，
resp_body:nil，resp_cookies:%{}，
响应头：[{“缓存控制”，“最大年龄=0，私有，必须重新验证”}，
{“x-request-id”，“bn5l49vfieh6mra9sq4toa9afcocq5c9”}，scheme:：http，
脚本名称：[]，
密钥库：“A2LVGKIq88H3nrx6cx4PC7uW
%Plug.Conn{adapter: {Plug.Adapters.Cowboy.Conn, :...}, assigns: %{},
 before_send: [#Function<1.66364769/1 in Plug.Logger.call/2>,
  #Function<0.78287744/1 in Phoenix.LiveReloader.before_send_inject_reloader/1>],
 body_params: %{}, cookies: %Plug.Conn.Unfetched{aspect: :cookies},
 halted: false, host: "127.0.0.1", method: "DELETE", owner: #PID<0.2060.0>,
 params: %{}, path_info: ["api", "v1", "sessions"],
 peer: {{127, 0, 0, 1}, 63006}, port: 4000,
 private: %{PhoenixExample.Router => {[], %{}},
   :guardian_default_claims => {:ok,
    %{"aud" => "User:96900", "exp" => 1474754356, "iat" => 1472162356,
      "iss" => "PhoenixExample", "jti" => "8947def5-ec3e-46e1-866d-2a1e9e16fd1f",
      "pem" => %{}, "sub" => "User:96900", "typ" => "token"}},
   :guardian_default_jwt => "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJVc2VyOjk2OTAwIiwiZXhwIjoxNDc0NzU0MzU2LCJpYXQiOjE0NzIxNjIzNTYsImlzcyI6IkNhbGx5YWNvcmUiLCJqdGkiOiI4OTQ3ZGVmNS1lYzNlLTQ2ZTEtODY2ZC0yYTFlOWUxNmZkMWYiLCJwZW0iOnt9LCJzdWIiOiJVc2VyOjk2OTAwIiwidHlwIjoidG9rZW4ifQ.BTYn7wjPlosztNmy3DKeRExzwBOiUG_ZLBJqUzUinDIpEl0xvUnb3EzYM7VaBpIT__JtVfZ0t7XET9D0LK0eMg",
   :guardian_default_resource => %PhoenixExample.User{__meta__: #Ecto.Schema.Metadata<:loaded, "users">,
    account: nil, address: nil, approved: false, city: nil, country: nil,
    description: nil, email: "radosch@me.com",
    encrypted_password: "$2b$12$E8AOMRI6pVHLIuumenHMSOfCR8TRK4.HYaCSGQvrobgTYkWBdcV7m",
    firstname: nil, guid: nil, id: 96900,
    inserted_at: #Ecto.DateTime<2016-08-05 01:06:19>, is_provider: false,
    lastname: nil, password: nil, postcode: nil, tags: nil,
    updated_at: #Ecto.DateTime<2016-08-05 01:06:19>, username: "radosch"},
   :phoenix_action => :delete,
   :phoenix_controller => PhoenixExample.SessionController,
   :phoenix_endpoint => PhoenixExample.Endpoint, :phoenix_format => "json",
   :phoenix_layout => {PhoenixExample.LayoutView, :app},
   :phoenix_pipelines => [:api],
   :phoenix_route => #Function<61.48695856/1 in PhoenixExample.Router.match_route/4>,
   :phoenix_router => PhoenixExample.Router,
   :phoenix_view => PhoenixExample.SessionView,
   :plug_session_fetch => #Function<1.82590416/1 in Plug.Session.fetch_session/1>},
 query_params: %{}, query_string: "", remote_ip: {127, 0, 0, 1},
 req_cookies: %Plug.Conn.Unfetched{aspect: :cookies},
 req_headers: [{"host", "127.0.0.1:4000"}, {"content-length", "0"},
  {"connection", "keep-alive"}, {"accept", "*/*"},
  {"user-agent", "CallYa/1 CFNetwork/808.0.1 Darwin/16.0.0"},
  {"accept-language", "de-ch"},
  {"authorization",
   "Bearer eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJVc2VyOjk2OTAwIiwiZXhwIjoxNDc0NzU0MzU2LCJpYXQiOjE0NzIxNjIzNTYsImlzcyI6IkNhbGx5YWNvcmUiLCJqdGkiOiI4OTQ3ZGVmNS1lYzNlLTQ2ZTEtODY2ZC0yYTFlOWUxNmZkMWYiLCJwZW0iOnt9LCJzdWIiOiJVc2VyOjk2OTAwIiwidHlwIjoidG9rZW4ifQ.BTYn7wjPlosztNmy3DKeRExzwBOiUG_ZLBJqUzUinDIpEl0xvUnb3EzYM7VaBpIT__JtVfZ0t7XET9D0LK0eMg"},
  {"accept-encoding", "gzip, deflate"}], request_path: "/api/v1/sessions",
 resp_body: nil, resp_cookies: %{},
 resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"},
  {"x-request-id", "bn5l49vfieh6mra9sq4toa9afcocq5c9"}], scheme: :http,
 script_name: [],
 secret_key_base: "A2LVGKIq88H3nrx6cx4PC7uWf/AAe9zcjwfCRFTx1X5xQ5KNvlLTzfxbGQxQctdb",
 state: :unset, status: nil}
%Plug.Conn{adapter: {Plug.Adapters.Cowboy.Conn, :...}, assigns: %{},
 before_send: [#Function<1.66364769/1 in Plug.Logger.call/2>,
  #Function<0.78287744/1 in Phoenix.LiveReloader.before_send_inject_reloader/1>],
 body_params: %{}, cookies: %Plug.Conn.Unfetched{aspect: :cookies},
 halted: false, host: "127.0.0.1", method: "DELETE", owner: #PID<0.2061.0>,
 params: %{}, path_info: ["api", "v1", "sessions"],
 peer: {{127, 0, 0, 1}, 63007}, port: 4000,
 private: %{PhoenixExample.Router => {[], %{}},
   :guardian_default_claims => {:ok,
    %{"aud" => "User:96900", "exp" => 1474754356, "iat" => 1472162356,
      "iss" => "PhoenixExample", "jti" => "8947def5-ec3e-46e1-866d-2a1e9e16fd1f",
      "pem" => %{}, "sub" => "User:96900", "typ" => "token"}},
   :guardian_default_jwt => "eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJVc2VyOjk2OTAwIiwiZXhwIjoxNDc0NzU0MzU2LCJpYXQiOjE0NzIxNjIzNTYsImlzcyI6IkNhbGx5YWNvcmUiLCJqdGkiOiI4OTQ3ZGVmNS1lYzNlLTQ2ZTEtODY2ZC0yYTFlOWUxNmZkMWYiLCJwZW0iOnt9LCJzdWIiOiJVc2VyOjk2OTAwIiwidHlwIjoidG9rZW4ifQ.BTYn7wjPlosztNmy3DKeRExzwBOiUG_ZLBJqUzUinDIpEl0xvUnb3EzYM7VaBpIT__JtVfZ0t7XET9D0LK0eMg",
   :guardian_default_resource => %PhoenixExample.User{__meta__: #Ecto.Schema.Metadata<:loaded, "users">,
    account: nil, address: nil, approved: false, city: nil, country: nil,
    description: nil, email: "radosch@me.com",
    encrypted_password: "$2b$12$E8AOMRI6pVHLIuumenHMSOfCR8TRK4.HYaCSGQvrobgTYkWBdcV7m",
    firstname: nil, guid: nil, id: 96900,
    inserted_at: #Ecto.DateTime<2016-08-05 01:06:19>, is_provider: false,
    lastname: nil, password: nil, postcode: nil, tags: nil,
    updated_at: #Ecto.DateTime<2016-08-05 01:06:19>, username: "radosch"},
   :phoenix_action => :delete,
   :phoenix_controller => PhoenixExample.SessionController,
   :phoenix_endpoint => PhoenixExample.Endpoint, :phoenix_format => "json",
   :phoenix_layout => {PhoenixExample.LayoutView, :app},
   :phoenix_pipelines => [:api],
   :phoenix_route => #Function<61.48695856/1 in PhoenixExample.Router.match_route/4>,
   :phoenix_router => PhoenixExample.Router,
   :phoenix_view => PhoenixExample.SessionView,
   :plug_session_fetch => #Function<1.82590416/1 in Plug.Session.fetch_session/1>},
 query_params: %{}, query_string: "", remote_ip: {127, 0, 0, 1},
 req_cookies: %Plug.Conn.Unfetched{aspect: :cookies},
 req_headers: [{"host", "127.0.0.1:4000"}, {"content-length", "0"},
  {"connection", "keep-alive"}, {"accept", "*/*"},
  {"user-agent", "CallYa/1 CFNetwork/808.0.1 Darwin/16.0.0"},
  {"accept-language", "de-ch"},
  {"authorization",
   "Bearer eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJVc2VyOjk2OTAwIiwiZXhwIjoxNDc0NzU0MzU2LCJpYXQiOjE0NzIxNjIzNTYsImlzcyI6IkNhbGx5YWNvcmUiLCJqdGkiOiI4OTQ3ZGVmNS1lYzNlLTQ2ZTEtODY2ZC0yYTFlOWUxNmZkMWYiLCJwZW0iOnt9LCJzdWIiOiJVc2VyOjk2OTAwIiwidHlwIjoidG9rZW4ifQ.BTYn7wjPlosztNmy3DKeRExzwBOiUG_ZLBJqUzUinDIpEl0xvUnb3EzYM7VaBpIT__JtVfZ0t7XET9D0LK0eMg"},
  {"accept-encoding", "gzip, deflate"}], request_path: "/api/v1/sessions",
 resp_body: nil, resp_cookies: %{},
 resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"},
  {"x-request-id", "u3c2qbajf1a0fofhlg7hl4aa57gttqrl"}], scheme: :http,
 script_name: [],
 secret_key_base: "A2LVGKIq88H3nrx6cx4PC7uWf/AAe9zcjwfCRFTx1X5xQ5KNvlLTzfxbGQxQctdb",
 state: :unset, status: nil}