How do I add a subtree to an existing prefix in a new clone?

Question

I have a main repository with two subtrees in the "external/" folder.

When I clone the repository, it downloads all the files, including the code that I previously pushed after the Git subtree command.

I want to clone that main repository on another machine and recreate the subtree structure, but the Git subtree add command fails because the folder where I want to put the subtree in already contains the folder and files.

> git clone https://URL/<main>
> git remote add <component> https://URL/<component>
> cd <main>
> git subtree add --prefix external/<component> <component> master
ERROR: prefix 'external/<component>' already exists.

How do I solve this or, is there a better way to have the subtree structure recreated for new clone operations?

Answer 1

The point of Git subtree is that you don't need to "recreate" anything in another location or on another machine. When you clone the repository, it already contains the subtree as normal files via normal commits!

If you just want to "refresh" or "update" the contents of the subtree, try pull.

git subtree pull --prefix external/<component> <component> master

If for some reason (and could you please clarify) you really do want to start over, you need to remove the subdirectory and then re-add the subtree.

git rm -fr external/<component>
git commit -m "Removing old subtree"
git subtree add --prefix external/<component> <component> master