Re: Checking out on a different+partial directory

From: Jeff King <peff@peff.net>
Date: May 22, 2010, 05:48 UTC
Message-ID: <20100522054852.GB29118@coredump.intra.peff.net>
In-Reply-To: <19441.8259.634019.348195@winooski.ccs.neu.edu>

On Mon, May 17, 2010 at 06:53:55AM -0400, Eli Barzilay wrote:

Show 6 quoted lines

> Say that I have a repository at /some/dir, and a tree that contains
> most of its files at /another/dir (the second is a build directory,
> made with `git archive', so some files removed due to export-ignore
> attributes and some built files are present).
> 
> Is there a convenient way to make /some/dir usable as a repository?

Did you mean /another/dir? /some/dir is already a repository as per your description above (is it a bare repository or a regular one?).

Show 6 quoted lines

> Two things that I tried are
> 
>   git --work-tree=/another/dir reset --hard master
> 
> which one time, but then failed with "fatal: unable to read tree...",
> and another is

I would have thought that worked, assuming you were in /some/dir. And oddly, _some_ stuff works. I tried:

  mkdir repo && cd repo && git init
  echo content >file && git add . && git commit -m file
  git archive --format=tar --prefix=work/ HEAD | tar -C .. -xf -

to create the situation. Running

  cd repo
  git --work-tree=$PWD/../work diff-files
  git --work-tree=$PWD/../work diff

works as expected (the first one notices stat-dirtiness, and the second shows an empty diff). But then I get:

  $ git --work-tree=$PWD/../work reset --hard
  fatal: unable to read tree ea394696ee1f7f5b55ca0d97d37748933cf39095

So there is clearly a bug. I'll investigate.

Show 5 quoted lines

>   cp -a /some/dir/.git /another/dir
>   cd /another/dir
>   git reset --hard master
> 
> which looks like it can suffer from the same problem.

That should work, too.

> (It would be especially nice if there's a way to have only different
> files touched in /another/dir.)

Only different files will be rewritten, but git will have to read all of the files to determine their sha1 (usually it avoids this by checking stat info, but obviously your exported files will not match the stat info in the /another/dir's index).

-Peff