Can I add a git submodule with an All Rights Reserved license?

Question

I have a project with GPL v3 license. And it has git submodules with the MIT, Apache v2 and All Rights Reserved due Berne Convention.

Am I violating copyright having public git submodules with All Rights Reserved license?

I tried search and found these questions:

1. When does a dependency imply a derivative work?
2. I want to make my private github repo public; can I put part of it under MIT license, and keep the rest protected?
3. How can I use an MIT license for code but protect the copyright of photos in my repository?

But I am still not sure whether they are allowed or not.

Answer 1

Git repositories and submodules are just ways of organising and tracking changes to files. I doubt that any FLOSS license would have anything relevant to say whatsoever about including differently-licensed submodules in a Git repo.

What does matter is when projects of different licenses are compiled together. Normally GPL and ARR are not compatible. But that incompatibility exists whether the projects are submodules, included in the main repo, or in completely disconnected version control systems (or even if they aren't in a VCS).

If your question is not so much about the compatibility, but whether you are allowed to include a submodule of proprietary code which you don't own, it depends where the code comes from. If it is from another Github repository, then Github's Terms of Service allow you to - public Github repositories are in effect not allowed to truly be All Rights Reserved.