我在一个真实的项目中遇到了这个问题，并设法使用下面的最小步骤重现它。
编辑：这不是一个重复的问题。我看到另一个涉及git subtree add的问题，而这不是这里的情况。
场景是：我有一个大型存储库，我希望将项目的一小部分提供给其他人来处理，并最终在完成后将他们的工作合并回大型仓库。
问题是git subtree merge（以及相关的推/拉）总是导致虚假冲突。
这是完全失败：
root@devbox:/tmp/git-demo# ll
total 164
drwxr-xr-x 2 root root 4096 Dec 5 10:55 ./
drwxrwxrwt 9 root root 159744 Dec 5 10:55 ../
root@devbox:/tmp/git-demo# git init bigrepo
Initialized empty Git repository in /tmp/git-demo/bigrepo/.git/
root@devbox:/tmp/git-demo# cd bigrepo/
root@devbox:/tmp/git-demo/bigrepo# echo 1 > one.txt
root@devbox:/tmp/git-demo/bigrepo# echo 2 > two.txt
root@devbox:/tmp/git-demo/bigrepo# mkdir lib
root@devbox:/tmp/git-demo/bigrepo# echo 3 > lib/three.txt
root@devbox:/tmp/git-demo/bigrepo# echo 4 > lib/four.txt
root@devbox:/tmp/git-demo/bigrepo# git add -A :/
root@devbox:/tmp/git-demo/bigrepo# git commit -minitial
[master (root-commit) 8360303] initial
4 files changed, 4 insertions(+)
create mode 100644 lib/four.txt
create mode 100644 lib/three.txt
create mode 100644 one.txt
create mode 100644 two.txt
这是我为合作者准备一个小型仓库的地方：
root@devbox:/tmp/git-demo/bigrepo# git subtree split --prefix=lib
87938ea784d67b83d61e6292a85788f3bdb28fab
root@devbox:/tmp/git-demo/bigrepo# git checkout -b lib_br 87938ea784d67b83d61e6292a85788f3bdb28fab
Switched to a new branch 'lib_br'
root@devbox:/tmp/git-demo/bigrepo# git init ../smallrepo
Initialized empty Git repository in /tmp/git-demo/smallrepo/.git/
root@devbox:/tmp/git-demo/bigrepo# git remote add small ../smallrepo
root@devbox:/tmp/git-demo/bigrepo# git push small lib_br:work
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (4/4), 238 bytes | 0 bytes/s, done.
Total 4 (delta 0), reused 0 (delta 0)
To ../smallrepo
* [new branch] lib_br -> work
现在假装你是在另一台机器上工作的合作者。忽略我使用本地存储库的事实，使用github时问题是一样的。准备做一些工作：
root@devbox:/tmp/git-demo/bigrepo# cd ../collaborator/
root@devbox:/tmp/git-demo/collaborator# git clone ../smallrepo
Cloning into 'smallrepo'...
done.
root@devbox:/tmp/git-demo/collaborator# cd smallrepo/
root@devbox:/tmp/git-demo/collaborator/smallrepo# ls
four.txt three.txt
root@devbox:/tmp/git-demo/collaborator/smallrepo# git status
On branch work
Your branch is up-to-date with 'origin/work'.
nothing to commit, working directory clean
现在努力工作，在文件中添加一行：
root@devbox:/tmp/git-demo/collaborator/smallrepo# echo 3-too >> three.txt
root@devbox:/tmp/git-demo/collaborator/smallrepo# git commit -a -m"added a line"
[work feb5252] added a line
1 file changed, 1 insertion(+)
Collaborator发布他们的杰作：
root@devbox:/tmp/git-demo/collaborator/smallrepo# git push origin work:work2
Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 265 bytes | 0 bytes/s, done.
Total 3 (delta 0), reused 0 (delta 0)
To /tmp/git-demo/collaborator/../smallrepo
* [new branch] work -> work2
通常协作者会在这里推送到work分支，但我忘了让smallrepo成为一个简单的回购，所以他会推送到work2。与github相比，这并没有改变行为，并且对于你最终会看到的问题应该是无关紧要的。
合作者打包回家。现在再次回到我身边：
root@devbox:/tmp/git-demo/collaborator/smallrepo# cd ../../bigrepo
root@devbox:/tmp/git-demo/bigrepo# git checkout master
Switched to branch 'master'
root@devbox:/tmp/git-demo/bigrepo# ll
total 24
drwxr-xr-x 4 root root 4096 Dec 5 11:06 ./
drwxr-xr-x 5 root root 4096 Dec 5 10:59 ../
drwxr-xr-x 9 root root 4096 Dec 5 11:06 .git/
drwxr-xr-x 2 root root 4096 Dec 5 11:06 lib/
-rw-r--r-- 1 root root 2 Dec 5 11:06 one.txt
-rw-r--r-- 1 root root 2 Dec 5 11:06 two.txt
root@devbox:/tmp/git-demo/bigrepo# git subtree pull --prefix=lib small work2
From ../smallrepo
* branch work2 -> FETCH_HEAD
Auto-merging lib/three.txt
CONFLICT (add/add): Merge conflict in lib/three.txt
Automatic merge failed; fix conflicts and then commit the result.
现在有。单线改变不应该是冲突。我在大文件上看到了同样的事情，大变化，小变化，无关紧要。当git subtree merge处理时，任何一方触及的每个文件都会成为冲突。
那么，这是一个错误，还是我做错了什么？