From: Duy Nguyen <pclouds@gmail.com>
Date: Fri, 05 Dec 2014 01:33:55 GMT
Subject: Re: [PATCH/RFC v2] Squashed changes for multiple worktrees vs. submodules
Message-ID: <CACsJy8BWv8U6+sujEj8HgMGmgFJR_YgCroYHcG1jsoGtbVCD7Q@mail.gmail.com>
In-Reply-To: <5480BEB9.8070109@web.de>

On Fri, Dec 5, 2014 at 3:06 AM, Jens Lehmann <Jens.Lehmann@web.de> wrote:
> Wow, so the .git/config is shared between all worktrees? I
> suspect you have very good reasons for that,

most of config vars are at repo-level, not worktree-level, except
maybe submodule.* and something else. Technically we could use
"include.path" to point to a non-shared file, where we store
worktree-specific config.

> but I believe
> that'll make multiple work trees surprise the user from time
> to time when used with submodules. Because initializing a
> submodule in one worktree initializes it in all other
> worktrees too (I suspect other users regard "git submodule
> init" being a worktree local command too). And setting
> "submodule.<name>.update" to "none" will also affect all
> other worktrees. But I'd need to have separate settings for
> our CI server, e.g. to checkout the sources without the
> largish documentation submodule in one test job (=worktree)
> while checking out the whole documentation for another job
> building the setup in another worktree.
>
> And if I understand the "checkout: reject if the branch is
> already checked out elsewhere" thread correctly, I won't be
> able to build "master" in two jobs at the same time?

If you do "git checkout --to ... master^{}", it should run fine. I'm
still considering doing something better with the read-only refs, but
haven't found time to really think it through yet.

> Thanks. But I changed my mind about the details (now that I
> know about .git/config and multiple worktrees). I think you'd
> have to connect a .git directory in the submodule to the
> common git dir directly, as you cannot use the core.worktree
> setting (which could be different between commits due to
> renames) when putting it into <worktree>/.git/modules. And
> then you couldn't remove or rename a submodule anymore,
> because that fails when it contains a .git directory.
>
> Seems like we should put a "Warning: may do unexpected things
> when used with submodules" (with some examples about what might
> happen) in the multiple worktrees documentation. And I don't
> believe anymore that teaching submodules to use the common git
> dir makes that much sense after I know about the restrictions
> it imposes.

I'm ok with such a warning fwiw.
-- 
Duy