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

[Dmitry Gutov]

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.