Re: gitoxide-compatible licensing of Git's Rust code, was Re: [PATCH 6/7] xdiff: conditionally use Rust's implementation of xxhash

> On Fri, Sep 26, 2025 at 11:06:38AM +0100, Phillip Wood wrote:
> 
>>> If I understand the suggestion correctly, it's not to license it
>>> specifically to GitOxide. It's to use a permissive license (like GPL
>>> with linking exception) that would make it compatible with other
>>> projects with similar licenses (like GitOxide).
>>
>> I was responding to this paragraph in Johannes' message
>>
>>      Note the exception? For new Rust code (and of course excluding code
>>      that has been ported verbatim from GPLv2-licensed code), GPL v2
>>      could be used with an exception along these lines: This file is
>>      licensed under the GPL v2, with the exception that it can be freely
>>      used in the Gitoxide project.
>>
>> That suggestion is pretty close to what libgit2 has in its git.git-authors
>> file[1]. I'm not sure how practical it is to special case just one project
>> though.
> 
> Ah, yeah, I may have misunderstood the proposal then.
> 
> I don't think that really changes much with respect to my concern, which
> is for existing code.

> That probably needs to be explicitly granted
> permission to relicense, whether to a specific project or not, and it is
> hard to pinpoint a definitive author for a lot of it (even if many
> authors have agreed to relicensing) because it has been touched by so
> many people over the years.
> 
> So there are probably two separate legal issues to consider:
> 
>    - how the explicit re-licensing grant is worded
> 
>    - what problems may came up with porting existing code that has been
>      touched by many people