Ruby on rails Can'；t使用find_for_facebook_oauth-what'；oauth有什么问题吗？

我稍微重写了

find\u for\u facebook\u oauth

方法，允许我的用户将他们的facebook帐户合并到他们的当前帐户。我还修改了方法来创建一个新的参与者（链接到用户）

然而，当有人使用该方法时，我很少（并非总是！）收到

不能复制NilClass

错误。方法如下：

def self.find_for_facebook_oauth(auth, token, signed_in_resource=nil, facebook_referal_id)

user = User.where(:provider => auth.provider, :uid => auth.uid.to_s).first

#new user
if !user and !userbymail
logger.info "User not found. Creating new user in user.rb"
user = User.new(
       provider:auth.provider,
       uid:auth.uid,
       email:auth.info.email,
       password:Devise.friendly_token[0,20]
       )
logger.info "Received FB information"
user.skip_confirmation!   #to skip the email
logger.info "Skipped the mail"
user.accepted_tos = true

#Only add participant if new user is saved
logger.info "Now saving user"
if user.save
  logger.info "User saved"
#name:auth.extra.raw_info.name,
  @participant = Participant.new
  @participant.user_id = user.id
  @participant.lastname = "Pan"
  @participant.dob = Time.now - 18.years
  @participant.firstname = auth.extra.raw_info.first_name || "Secret"
  @participant.lastname = auth.extra.raw_info.last_name || "Secret"
  if auth.extra.raw_info.gender == "male"
    @participant.gender = 2
  elsif auth.extra.raw_info.gender == "female"
    @participant.gender = 1
  else
    @participant.gender = 4
  end
  @participant.dob = Date.strptime(auth["extra"]["raw_info"]["birthday"],'%m/%d/%Y') || Time.now - 18.years
  @participant.nationality = "AQ"

我不明白哪里会出问题。从facebook传来的消息可能是空的吗？我看了一下错误，但找不出哪里出了问题

app web.1     - - (facebook) Callback phase initiated.
app web.1     - - Processing by Users::OmniauthCallbacksController#facebook as HTML
app web.1     - -   Parameters: {"state"=>"f357f10d5f136b28732465968ee29451af9406391ecd1144", "code"=>"AQAUePnXS7qggpjUE0gNPuPHODFOcfd6vo2zJvl4KCCrH8Mp2j4_6PS5t71R_PeHCJaFpM_ERjb9QWHqUkP6OB7WPI22Q16y1YwfwKy7IHxlz5q56DoCINMzh3MuYgKTJRFjs3XAKOo-Ncf7jigmlp1GADlBW1aB-F-5oUGpNQw1GcFVyPAnOwXD3B3wr82FO0om_z7uhXDtEDf2_RP14Vo5"}
app web.1     - - Geocoder call
app web.1     - - Italy
app web.1     - -   User Load (3.3ms)  SELECT "users".* FROM "users" WHERE "users"."provider" = 'facebook' AND "users"."uid" = '1503444170' LIMIT 1
app web.1     - -   User Load (28.5ms)  SELECT "users".* FROM "users" WHERE "users"."email" = 'app+4ss3t1sal5.1cppf6a.d25032a0cdac6d19ac26ad2c44e14cb@proxymail.facebook.com' LIMIT 1
app web.1     - - User not found. Creating new user in    user.rb
app web.1     - -    (44.0ms)  BEGIN
app web.1     - -   User Exists (2.0ms)  SELECT 1 AS one FROM "users" WHERE "users"."email" = 'app+4ss3t1sal5.1cppf6a.d25089e10cdac6d19ac26ad2c44e14cb@proxymail.facebook.com' LIMIT 1
heroku nginx  - - 2.230.67.191 - - [06/Apr/2013:11:16:42 +0000] "GET /users/auth/facebook/callback?state=f357f10d5f136b28732465968ee29451af9406391ecd1144&code=AQAUePnXS7qggpjUE0gNPuPHODFOcfd6vo2zJvl4KCCrH8Mp2j4_6PS5t71R_PeHCJaFpM_ERjb9QWHqUkP6OB7WPI22Q16y1YwfwKy7IHxlz5q56DoCINMzh3MuYgKTJRFjs3XAKOo-Ncf7jigmlp1GADlBW1aB-F-5oUGpNQw1GcFVyPAnOwXD3B3wr82FO0om_z7uhXDtEDf2_RP14Vo5 HTTP/1.1" 500 763 "-" "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.43 Safari/537.31" www.thestudentranking.com
heroku router - - at=info method=GET path=/users/auth/facebook/callback?state=f357f10d5f136b28732465968ee29451af9406391ecd1144&code=AQAUePnXS7qggpjUE0gNPuPHODFOcfd6vo2zJvl4KCCrH8Mp2j4_6PS5t71R_PeHCJaFpM_ERjb9QWHqUkP6OB7WPI22Q16y1YwfwKy7IHxlz5q56DoCINMzh3MuYgKTJRFjs3XAKOo-Ncf7jigmlp1GADlBW1aB-F-5oUGpNQw1GcFVyPAnOwXD3B3wr82FO0om_z7uhXDtEDf2_RP14Vo5 host=www.thestudentranking.com fwd="2.230.67.191" dyno=web.1 connect=3ms service=705ms status=500 bytes=763
app web.1     - -   SQL (41.7ms)  INSERT INTO "users" ("accepted_tos", "confirmation_sent_at", "confirmation_token", "confirmed_at", "created_at", "current_sign_in_at", "current_sign_in_ip", "email", "encrypted_password", "faked", "last_sign_in_at", "last_sign_in_ip", "provider", "remember_created_at", "reset_password_sent_at", "reset_password_token", "sign_in_count", "uid", "unconfirmed_email", "updated_at") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20) RETURNING "id"  [["accepted_tos", true], ["confirmation_sent_at", nil], ["confirmation_token", nil], ["confirmed_at", Sat, 06 Apr     2013 13:16:42 CEST +02:00], ["created_at", Sat, 06 Apr 2013 13:16:42 CEST +02:00], ["current_sign_in_at", nil], ["current_sign_in_ip", nil], ["email", "app+4ss3t1sal5.1cppf6a.d25089e10cdac6d19ac26ad2c44e14cb@proxymail.facebook.com"], ["encrypted_password", "$2a$10$xjK8Y0zpkdE/PZnT4cSQ5uuJQ/KaPfkhbxFtvYXJSyAAZWV5emy4K"], ["faked", nil], ["last_sign_in_at", nil], ["last_sign_in_ip", ni
app web.1     - - l], ["provider", "facebook"], ["remember_created_at", nil], ["reset_password_sent_at", nil], ["reset_password_token", nil], ["sign_in_count", 0], ["uid", "1503444170"], ["unconfirmed_email", nil], ["updated_at", Sat, 06 Apr 2013 13:16:42 CEST +02:00]]
app web.1     - -    (12.1ms)  COMMIT
app web.1     - - Completed 500 Internal Server Error in 329ms
app web.1     - -
app web.1     - - TypeError (can't dup NilClass):  app/models/user.rb:91:in `find_for_facebook_oauth'
    app/controllers/users/omniauth_callbacks_controller.rb:12:in `facebook' EXCEPT
app web.1     - -
app web.1     - -
app web.2     - - Started GET "/" for 2.230.67.191 at 2013-04-06 11:16:45 +0000

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关于错误以及如何避免/抓住错误的线索将非常有用。谢谢。

我的api代码已经运行了几个月，但是突然/me/posts位停止了工作。即使是graph API测试页面也不起作用！developers.facebook.com/tools/explorer/145634995501895/…