Re: git submodule vs GIT_WORK_TREE

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 26, 2012, 22:53 UTC
Message-ID: <7vzk7p8z38.fsf@alter.siamese.dyndns.org>
In-Reply-To: <4FEA380D.8070001@web.de>

Jens Lehmann <Jens.Lehmann@web.de> writes:

Show 20 quoted lines

> Am 26.06.2012 21:51, schrieb Junio C Hamano:
> ...
>> If the user has to use GIT_WORK_TREE to mark the root level of the
>> superproject working tree as such, it is very likely that the
>> controlling repository of the superproject does not live in the
>> $GIT_WORK_TREE/.git directory (in other words, $GIT_DIR points at
>> somewhere else).  Exporting GIT_WORK_TREE/submodule as the new value
>> of GIT_WORK_TREE is sensible, but I do not see a reasonable way to
>> deduce the value of GIT_DIR for the submodule in such a case.  The
>> controlling repository of the superproject is located somewhere
>> random; there is no reason to assume the repository for the
>> submodule is somewhere at fixed relation to it.
>> 
>> Does it mean the short answer to Richard's situation is "Don't do
>> it"?  I am not sure, but it is starting to sound like it.
>
> Not at all, I was just trying to reach consensus on what the user
> can reasonably expect when setting GIT_WORK_TREE in the presence of
> submodules. I will look into it to see how we can handle the cases
> where GIT_WORK_TREE and/or GIT_DIR are set.

Thanks, then I'll let you look into it. I do not see how you could determine GIT_DIR for the submodule sensibly if the superproject's working tree does not have its GIT_DIR as ".git" at the top-level, though.

Declaring that a checked out submodule _must_ have its controlling repository as ".git" at its root level, i.e. it should be accessible without using GIT_WORK_TREE/GIT_DIR at all just like a normal Git repository is, would be a clean way to avoid the issue altogether and it still will allow the top-level superproject to be structured in a funny way to require GIT_WORK_TREE/GIT_DIR to access it, but I am not sure if that is too restrictive for people who for some unknown reason want to use these environment variables to create repositories with a strange layout.