Git 子树拉取导致合并冲突

Question

Currently I have 3 repositories, named A, B, and C. Both A and B have a folder called c which is a subtree of repository C. Now, when I add a new file to A's c, do a git add, commit and a git subtree push, it gets pushed to C. When I do a pull in B, it ends up in B's c folder, so that works like expected. But when I then edit the new file in B's c and do a git commit and git subtree push and I do a git subtree pull in A, I get a merge conflict.

How do I prevent this conflict?

Answer 1

I was curious (perhaps suspicious) about whether this part of your description might be relevant. You said "Currently I have 3 repositories, named A, B, and C. Both A and B have a folder called c which is a subtree of repository C ."

When I work with subtrees, the shared subtree is hosted by a bare repository that is entirely devoted to that shared subtree content. So, if one wants to have a shared folder f, then there is a bare repository F that holds all the files that would go into the shared folder f and nothing else. The F repository doesn't have other content. It wouldn't have a folder f as a portion of the F repository. The F repository is bare (no working tree content).

Then, if I have three projects, A, B, and C, that all want to use folder f, that folder f is contained in each of A, B, and C as a subtree and all three will pull from and push to the bare repository F. F is the hub and the others (A, B, and C) are spokes. Each spoke exchanges with the hub, but not directly with each other. A and B don't push to or pull from C, for example.

From your description, that would be my best guess about what might be leading to your problem. Try making sure that the central host repository of the subtree is only a bare repository that is not used to hold anything else or any working tree content.

ps While I do have a local bare repository to host the shared subtree (which allows working even when not connected to the inte.net -- a foundational benefit of distributed version control), one can also periodically push the changes in the updated local bare repository to a remote bare repository for safe keeping. However, in this configuration, I don't recommend trying to have multiple developers make independent changes to the same shared subtree. If you have multiple developers working on the shared subtree code, then just use one shared remote bare repository at whatever service you use for shared remote repositories.

Extra tip: IF one is working with a local bare repository (because of working with a subtree), that can be less than ideal because there is (so far) poor support for working with a local bare repository on your computer. While in a Windows environment with Git for Windows, if I cd into the top directory of the bare repository, then the gitk command will bring up a usable gui tool that lets one examine the bare repository.