我正试图将我的本地数据库放在Heroku上现有的应用程序中，结果出现了以下错误：
Sending schema
Schema: 100% |==========================================| Time: 00:00:07
Sending indexes
schema_migrat: 100% |==========================================| Time: 00:00:00
Sending data
3 tables, 3,621 records
schema_migrat: 100% |==========================================| Time: 00:00:00
! Heroku client internal error.=== | ETA: 00:01:04
! Search for help at: https://help.heroku.com
! Or report a bug at: https://github.com/heroku/heroku/issues/new
Error: undefined method `headers' for nil:NilClass (NoMethodError)
Backtrace: /Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/utils.rb:173:in `reraise_server_exception'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:522:in `rescue in block (2 levels) in push_data_from_table'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:507:in `block (2 levels) in push_data_from_table'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/utils.rb:102:in `calculate_chunksize'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:491:in `block in push_data_from_table'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:481:in `loop'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:481:in `push_data_from_table'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:476:in `block in push_data'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:471:in `each'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:471:in `push_data'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:412:in `block in run'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:203:in `call'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:203:in `catch_errors'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/operation.rb:405:in `run'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/taps-0.3.24/lib/taps/cli.rb:172:in `clientxfer'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/heroku-2.30.3/lib/heroku/command/db.rb:192:in `taps_client'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/heroku-2.30.3/lib/heroku/command/db.rb:30:in `push'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/heroku-2.30.3/lib/heroku/command.rb:193:in `run'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/heroku-2.30.3/lib/heroku/cli.rb:25:in `start'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/gems/heroku-2.30.3/bin/heroku:16:in `<top (required)>'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/bin/heroku:19:in `load'
/Users/adam/.rvm/gems/ruby-1.9.2-p290/bin/heroku:19:in `<main>'
Command: heroku db:push
Plugins: heroku-sql-console
Version: heroku-gem/2.30.3 (x86_64-darwin10.8.0) ruby/1.9.2
奇怪的是，昨天一切都很好，我能够毫无问题地将我的本地数据库推送到Heroku。今天，我只是在数据库中添加了另一个列，并想实时推送它，结果出现了这个错误。
我尝试实时推送数据库3次，所有尝试都失败了。
哪里可能有问题？
帮助我指定所需的表：
heroku db:push --tables table1,table2