使用edeliver迁移数据库时出错

Question

我总是使用edeliver来部署我的应用，但在我的新应用中，我发现了一个奇怪的错误。

当我运行mix edeliver migrate production时，我收到了此回复：

EDELIVER MYPROJECT WITH MIGRATE COMMAND

-----> migrateing production servers

production node:

  user    : user
  host    : example.com
  path    : /home/user/app_release
  response: RPC to 'myproject@127.0.0.1' failed: {'EXIT',
                                      {#{'__exception__' => true,
                                         '__struct__' =>
                                          'Elixir.ArgumentError',
                                         message => <<"argument error">>},
                                       [{ets,lookup_element,
                                         ['Elixir.Ecto.Registry',nil,3],
                                         []},
                                        {'Elixir.Ecto.Registry',lookup,1,
                                         [{file,"lib/ecto/registry.ex"},
                                          {line,18}]},
                                        {'Elixir.Ecto.Adapters.SQL',sql_call,
                                         6,
                                         [{file,"lib/ecto/adapters/sql.ex"},
                                          {line,251}]},
                                        {'Elixir.Ecto.Adapters.SQL','query!',
                                         5,
                                         [{file,"lib/ecto/adapters/sql.ex"},
                                          {line,198}]},
                                        {'Elixir.Ecto.Adapters.MySQL',
                                         '-execute_ddl/3-fun-0-',4,
                                         [{file,"lib/ecto/adapters/mysql.ex"},
                                          {line,107}]},
                                        {'Elixir.Enum',
                                         '-reduce/3-lists^foldl/2-0-',3,
                                         [{file,"lib/enum.ex"},{line,1826}]},
                                        {'Elixir.Ecto.Adapters.MySQL',
                                         execute_ddl,3,
                                         [{file,"lib/ecto/adapters/mysql.ex"},
                                          {line,107}]},
                                        {'Elixir.Ecto.Migrator',
                                         '-migrated_versions/2-fun-0-',2,
                                         [{file,"lib/ecto/migrator.ex"},
                                          {line,44}]}]}}

但是当我输入mix edeliver restart production后跟迁移命令时，一切正常。为什么会这样？