Re: policy discussion on bundling ELPA packages in the emacs tarball

[Dmitry Gutov <dgutov@yandex.ru>]

On 26.01.2021 00:00, Stephen Leake wrote:
> Dmitry Gutov <dgutov@yandex.ru> writes:
> 
>> On 24.01.2021 22:15, Eli Zaretskii wrote:
>>> IMO, people who are interested only in packages bundled with Emacs
>>> should not need to have ELPA on their local machines.  Not even one
>>> checkout of ELPA should be needed.  They should just need to clone the
>>> Emacs Git repository (modulo the submodules-related options), and
>>> that's all.  Exactly like they do today: there's no need to clone ELPA
>>> to have a fully functional clone of the Emacs Git repository.
>>
>> Git allows one to check out one branch's contents, without the rest of
>> the repository.
> 
> Just to be clear, "checkout" means retrieve from a local git repository
> into a directory tree; that is always a single branch.

I referred to doing only a partial download, of course.

>> So said people wouldn't need to download the whole of ELPA, if you
>> were worried about that.
> 
> "clone" and "add submodule" download from the remote repository.
> 
> "add submodule -b <branch>" specifies what branch to checkout, but still
> downloads the whole repository.
> 
> Ah; "clone ... --single-branch --branch <branch>" allows downloading
> only that branch into the local repository. But you can't specify more
> than one branch, so that would be inconvenient for more than one bundled
> package.
> 
> And "git add submodule" does not accept --single-branch.

There is a pretty long description here: 
https://stackoverflow.com/questions/2144406/how-to-make-shallow-git-submodules, 
which I didn't have time to read whole.

But from a small experiment, here's what you can do:

git submodule add --depth 1 <repo> <new-module-path>
cd <new-module-path>
git fetch --depth 512 # or however more you need

There are also options like --shallow-since or --deepen.