1 为什么cloudfoundry的java buildpack会报这个错误？（heroku的java buildpack就不会）

 2014-10-08T21:58:37.55-0400 [STG]     ERR Cloning into '/tmp/buildpacks/java-buildpack'...
2014-10-08T21:58:41.39-0400 [STG]     OUT -----> Java Buildpack Version: c19642c | https://github.com/cloudfoundry/java-buildpack.git#c19642c
2014-10-08T21:58:41.39-0400 [STG]     ERR [Buildpack]                      ERROR Compile failed with exception #<RuntimeError: No container can run this application>
2014-10-08T21:58:41.39-0400 [STG]     ERR No container can run this application
2014-10-08T21:58:41.39-0400 [STG]     OUT Staging failed: Buildpack compilation step failed
2014-10-08T21:58:41.49-0400 [API]     ERR Encountered error: Staging error: failed to stage application:
2014-10-08T21:58:41.49-0400 [API]     ERR Script exited with status 1

2 为什么cf push不加-f选项会报错？

 2014-10-08T21:49:45.08-0400 [API]     ERR Encountered error: Staging error: failed to stage application:
2014-10-08T21:49:45.08-0400 [API]     ERR Script exited with status 1

3 用了heroku的java buildpack偶尔也会出现以下错误：

 OUT App instance exited with guid da98ec30-a083-49f4-9858-97ce6ffa4883 payload: {"cc_partition"=>"default", "droplet"=>"da98ec30-a083-49f4-9858-97ce6ffa4883", "version"=>"ffe23d29-1cfa-406c-b78d-5095ef93abe9", "instance"=>"be6d24c9250245eea68d2d83cd63e5f9", "index"=>0, "reason"=>"CRASHED", "exit_status"=>-1, "exit_description"=>"failed to start", "crash_timestamp"=>1412820950}

ps：用的cf客户端版本是6.6.0，cloudfoundry server是v2的版本