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

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Leake <stephen_leake@stephe-leake.org>
> Date: Fri, 22 Jan 2021 18:50:02 -0800
> Cc: emacs-devel <emacs-devel@gnu.org>
> 
> > How does that work with ELPA sub-modules? Git worktrees I think hard
> > links, so the files sizes are much smaller, but with submodules I am
> > going to get some of ELPA and it's .git multiple times?
> 
> Hmm. Perusing https://git-scm.com/docs/gitsubmodules hints that the
> submodules could be worktrees if the "Git directory located under the
> $GIT_DIR/modules/" can be a worktree link, but there's no option for
> 'git submodule add' to specify that.
> 
> Doing a web search found:
> 
> https://stackoverflow.com/questions/31871888/what-goes-wrong-when-using-git-worktree-with-git-submodules
> 
> which says using worktrees that contain submodules is not a good idea.
> 
> and
> https://github.com/git/git/commit/1a248cf21d450eb911d01a89c84412c2da365e66
> 
> which is 4 years old, but indicates that mixing worktrees and submodules
> was an issue then.
> 
> I'll have to test some stuff. 

My impression is that some of the problems were fixed, but it will be
important to know which versions of Git fixed them, so that those who
use worktrees could decide whether they need to upgrade.

> If the submodules cannot be worktrees, then I think we have to
> abandon this approach.

I'm not sure.  There are alternatives to using worktrees, so the fact
that some of us use worktrees in some workflows should not necessarily
veto the submodule solution to integrating ELPA into Emacs, because
this integration is more important than personal workflows.

But maybe I misunderstand what you mean by "submodule cannot be
worktrees", because AFAIU Phillip raised an issue that is a different
one: whether submodules live well with different branches being
checked out in different worktrees -- there's nothing there to suggest
that submodules themselves should be worktrees.