Re: merging unmanaged working tree

[Avery Pennarun <apenwarr@gmail.com>]

2010/3/15 Łukasz Stelmach <lukasz.stelmach@iem.pw.edu.pl>:
> Avery Pennarun <apenwarr@gmail.com> writes:
>> a) Look at 'git clone --depth' so you can clone only the most recent
>> version of the files, not the *entire* repo.  This lets you do commits
>> on any computer you want with the pen drive plugged in, but saves
>> space.
>
> I've tried this one. It works (but why the --depht 1 gives two
> revisions?) but even thoug the main repository and the portable one have
> common commits I can't pull changes back from the mobile to the main
> one. Is there any wise trick to make git try a little harder?

I don't know; I haven't used shallow clones (ie. --depth) very much.
git's implementation of them seems a bit half-hearted.  The man page
says "A shallow repository has a number of limitations (you cannot
clone or fetch from it, nor push from nor into it), but is adequate if
you are only interested in the recent history of a large project with
a long history, and would want to send in fixes as patches."  There is
no technical reason for this limitation, as far as I know.

It does give a hint as to what you could do instead of push/pulling,
however: you could use git format-patch to extract the changes from
your shallow copy, and git am to import the patches back into your
main copy.  Seems like a pain though.

>> b) Keep your .git directory on your main PC's disk, and the working
>> tree on your pen drive.  Look at the GIT_DIR environment variable in
>> 'man git'.  Then when you bring the pen drive back to your PC, you
>> have the full repo available.  (If you use 'git clone --reference'
>> when making the new repo, the extra .git directory should take only
>> minimal space.)
>
> This one's nice and seems to be most space efficient as far as flash
> space is concerned. However, I'd be able to sync only with the machine
> that holds the portable GIT_DIR while the previous method, if only
> there was a way to make git work with shallow clones, could work with
> different hosts if I synec my No1 desktop with them too.

Maybe you could do something like:

      git clone -s ~/myrepo /pendrive/myrepo

This will give you a .git dir in /pendrive/myrepo, but all the
*objects* in the git repo will actually be borrowed from ~/myrepo.
This will make git virtually unusable on /pendrive/myrepo *unless* you
mount the disk on a PC that has ~/myrepo in the original location.  On
any such computer, you could be able to do normal git operations in
/pendrive/myrepo, including pulling changes from there to ~/myrepo.

As you do git operations on /pendrive, /pendrive/myrepo/.git will
slowly accumulate objects that you might have to clear out over time
(ie. after pushing them to the parent repo).

> I've just invented yet another method. Push the content to the pendrive:
>
> $ git commit -am branching
> $ git archive --format tar HEAD | tar -C /media/pendrive/project -xf -
> $ git log -1 > /media/pendrive/project/HEAD # to remember
> [...]

Yeah, I guess you could do that, but at that point you're basically
not using git anymore.

Have fun,

Avery