Perforce 性能+；来自p4 diff2的reviewboard输出无法上载到review board

我使用以下命令生成了diff文件

p4 diff2 -duw //depot/mainbrach... //depot/proj_branch... |  grep -v "identical" > changes.diff

我尝试使用rbt工具使用此差异文件创建审阅请求

rbt post --diff-filename=changes.diff --server=http://XXX

我得到以下错误

 ERROR: Error uploading diff
 The generated diff file was empty. This usually means no files were modified in this change.Your review request still exists, but the diff is not attached.

我还发现diff格式与reviewboard接受的格式不同（与旧的reviewdiff文件相比）

网上的一些地方提到，可以使用事后审查或外部工具来纠正相同的错误。但无法找到确切的解决方案。 请帮帮我 提前谢谢