Re: [PATCH 1/2] store submodule in common dir

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 14, 2018, 23:20 UTC
Message-ID: <xmqqk1osy1qo.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <xmqqo9e4y2gr.fsf@gitster-ct.c.googlers.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 10 quoted lines

> My understanding of what Joakim wants to do is to have a top-level
> project that has three subdirectories, e.g. kernel/v2.2, kernel/v2.4
> and kernel/v2.6, each of which is a submodule that houses these
> versions of Linux kernel source, but only clone Linus's repository
> (as the up-to-late tree has all the necessary history to check out
> these past development tracks).  And that should be doable with
> just the main checkout, without any additional worktree (it's just
> the matter of having .git/modules/kernel%2fv2.6/ directory pointed
> by two symlinks from .git/modules/kernel%2fv2.[24], or something
> like that).

Actually I take the last part of that back. When thought naively about, it may appear that it should be doable, but because each of the modules/* directory in the top-level project has to serve as the $GIT_DIR for each submodule checkout, and the desire is to have these three directories to have checkout of three different branches, a single directory under modules/. that is shared among three submodules would *not* work---they must have separate index, HEAD, etc.

Theoretically we should be able to make modules/kernel%2fv2.[24] additional "worktree"s of modules/kernel%2fv2.6, but given that these are all "bare" repositories without an attached working tree, I am not sure how that would supposed to work. Thinking about having multiple worktrees on a single bare repository makes me head spin and ache X-<;-)