Re: How de-duplicate similar repositories with alternates

From: Stefan Beller <sbeller@google.com>
Date: Nov 29, 2018, 18:55 UTC
Message-ID: <CAGZ79ka1sjU+rHctRP4SVMP0GQsK2iZghkU46=f96ugqvX5Neg@mail.gmail.com>
In-Reply-To: <87zhtsx73l.fsf@evledraar.gmail.com>

On Thu, Nov 29, 2018 at 7:00 AM Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:

Show 5 quoted lines

>
> A co-worker asked me today how space could be saved when you have
> multiple checkouts of the same repository (at different revs) on the
> same machine. I said since these won't block-level de-duplicate well[1]
> one way to do this is with alternates.

Another way is to use git-worktree, which would solve the gc issues mentioned below?

I view alternates as a historic artefact as the deduping of objects client side can be done using worktrees, and on the serverside - I think - most of the git hosters use namespaces and put a fork network into the same repository and use pack islands.

Can you elaborate on why worktrees would not solve the problem? (I initially was hesitant to use them as I liked going into .git and tempering with files such as the config directly. But now I cannot `cd .git` any more; it turns out the advantages outweigh this corner case that I was attached to)