Re: Behavior of 'git fetch' for commit hashes

From: Jonathan Tan <jonathantanmy@google.com>
Date: Jun 19, 2017, 17:49 UTC
Message-ID: <20170619104936.706eff69@twelve2.svl.corp.google.com>
In-Reply-To: <14e804c6-0798-8bbd-b182-66c3cd2b870c@vaisala.com>

On Mon, 19 Jun 2017 12:09:28 +0000 <eero.aaltonen@vaisala.com> wrote:

Show 8 quoted lines

> For version 2.7.4
> =================
> Git exits with exit code 1.
> 
> However, if I first do 'git fetch <branch>', then 'git fetch <sha1> will
> also work
> 
>  * branch   <sha1> -> FETCH_HEAD

I suspect that what is happening is that 'git fetch <branch>' also downloads the commit referenced by <sha1>, so the subsequent 'git fetch <sha1>' is a no-op (except setting FETCH_HEAD).

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> For version 2.13.3
> ==================
> Git exits with exit code 128 and message
> fatal: Couldn't find remote ref
> 
> However, the workaround for descbibed abot for git version 2.7.4 no
> longer works. The result is always
> fatal: Couldn't find remote ref

I'll take a look into this.

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> Desired result
> ==============
> Commit is in .git/FETCH_HEAD and can be checked out.
> 
> 
> I want to checkout a specific commit without creating any extra named
> remotes in the local git clone.
> 
> Finally,
> What is the expected behavior for 'git fetch' in this case?
> Is there some other way I can achieve my goals?

I'll take a look into the expected behavior, but if my assumptions are correct, you should be able to just checkout the commit you want after fetching the branch:

  git fetch <forkUrl> <branch>
  git checkout <sha1>