我一直在努力解决一些错误并进入 heroku 部署，但是，在“检查 url”阶段它返回 500 错误。
这是错误日志：
2014-07-31T10:13:11.761170+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=03eaab71-cd78-4715-801f-4fb05622a198 fwd="50.19.68.232" dyno=web.1 connect=1 service=105 status=500 bytes=416
2014-07-31T10:13:12.771487+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=e9b02357-e2e4-4960-b64c-634c709c8fab fwd="23.20.32.241" dyno=web.1 connect=1 service=10 status=500 bytes=353
2014-07-31T10:13:13.789492+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=4166b47b-d8ae-4575-9565-82d73a44e1d4 fwd="81.174.137.46" dyno=web.1 connect=1 service=10 status=500 bytes=579
2014-07-31T10:13:13.923179+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=devonite.herokuapp.com request_id=639e99d7-b09a-443c-9386-bdd4ed62a482 fwd="81.174.137.46" dyno=web.1 connect=1 service=9 status=404 bytes=519
2014-07-31T10:13:17.960963+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=c2a7accf-9255-4b64-950e-d901af340ca4 fwd="23.20.32.241" dyno=web.1 connect=1 service=10 status=500 bytes=350
2014-07-31T10:13:23.142767+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=bcd19568-5ba9-43cc-bb54-88a46be49328 fwd="23.20.32.241" dyno=web.1 connect=1 service=9 status=500 bytes=350
2014-07-31T10:13:28.352289+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=14328198-695a-4f01-9107-b928fcf0739b fwd="23.20.32.241" dyno=web.1 connect=1 service=19 status=500 bytes=350
2014-07-31T10:13:33.555051+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=c9942c91-924a-4eda-828d-c1ecb7db88a0 fwd="23.20.32.241" dyno=web.1 connect=2 service=11 status=500 bytes=350
2014-07-31T10:13:38.886327+00:00 heroku[router]: at=info method=GET path="/" host=devonite.herokuapp.com request_id=64241c67-e519-4927-99b9-c25b4dbc0028 fwd="81.174.137.46" dyno=web.1 connect=1 service=10 status=500 bytes=605
知道这可能是什么吗？作为 rails 和 heroku 的新手，我正在努力调试它！