git subtree我帮不上忙，但是filter-branch可以帮上忙.

I can't help you with git subtree, but with filter-branch it's possible.

首先，您需要创建一个公共存储库，其中将包含源分支和目标分支.这可以通过在来源"旁边添加新的远程"并从新的远程获取来完成.

First you need to create a common repository that will contain both source and destination branches. This can be done by adding a new "remote" beside "origin" and fetching from the new remote.

在源分支上使用filter-branch到rm -rf除dir-to-move以外的所有目录.之后，您将拥有一个提交历史记录，该记录可以被完全地重新建立基础或合并到目标分支中.我认为最简单的方法是从源分支中cherry-pick所有非空提交.这些提交的列表可以通过运行git rev-list --reverse source-branch -- dir-to-move

Use filter-branch on the source branch to rm -rf all directories except dir-to-move. After that you'll have a commit history that can be cleanly rebased or merged into the destination branch. I think the easiest way is to cherry-pick all non-empty commits from the source branch. The list of these commits can be obtained by running git rev-list --reverse source-branch -- dir-to-move

当然，如果dir-to-move的历史记录是非线性的(已经包含合并提交)，那么它不会被Cherry-pick保留，因此可以使用git merge代替.

Of course, if the history of dir-to-move is non-linear (already contains merge commits), then it won't be preserved by cherry-pick, so git merge can be used instead.

创建公共仓库的示例:

cd repo-2
git remote add source ../repo-1
git fetch source

示例过滤器分支

cd repo-2
git checkout -b source-master source/master
CMD="rm -rf dir1 dir2 dir3 dir5"
git filter-branch --tree-filter "$CMD"

示例性地摘录到目标主机

Example cherry-pick into destination master

cd repo-2
git checkout master
git cherry-pick `git rev-list --reverse source-master -- dir-to-move`