rails升级后资产预编译失败

Question

我刚刚从Rails 4.0.4升级到4.1.8，当我在Heroku上推送到我们的登台服务器时，我收到以下错误

Removing jquery-rails (3.0.4)
-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile
       rake aborted!
       NoMethodError: undefined method `[]=' for nil:NilClass
       /tmp/build_6e5605f8ccbbe1dcb495bb63b761220d/config/initializers/puma_database_connection.rb:7:in `block (2 levels) in <top (required)>'
       /tmp/build_6e5605f8ccbbe1dcb495bb63b761220d/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
       /tmp/build_6e5605f8ccbbe1dcb495bb63b761220d/vendor/bundle/ruby/2.0.0/gems/activesupport
       /tmp/build_6e5605f8ccbbe1dcb495bb63b761220d/vendor/bundle/ruby/2.0.0/gems/railties-
       Tasks: TOP => environment
       (See full trace by running task with --trace)
 !
 !     Precompiling assets failed.

当我运行资产时：预编译RAILS_ENV =开发，它可以正常工作

有什么建议吗？