Re: [PATCH v2 0/1] rev-list: add --missing-only option to filter output

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 1, 2026, 19:57 UTC
Message-ID: <xmqq1pbcsq1h.fsf@gitster.g>
In-Reply-To: <20260901185100.33948-1-siddharthasthana31@gmail.com>

Siddharth Asthana <siddharthasthana31@gmail.com> writes:

> At GitLab, Gitaly uses rev-list --missing=print on partial clones to
> find missing objects. The output mixes present and missing objects and
> prefixes missing ones with '?', so we post-process it. --missing-only
> avoids that.

Not an objection to the feature (as it can already be done with post-processing), but stepping back a bit, how is this list of missing objects used?

You know what objects you currently have. They refer to other objects, some of which you may lack. You can get a list of them, and then what? After fetching them from 'origin', you will have a new set of missing objects (e.g., after fetching a missing commit, its parents become known and missing; after fetching a missing tree, the blobs and trees contained in it become known and missing).

Fetching missing objects a batch at a time sounds like too much back-and-forth to peel the onion, if the process using '--missing-only' is trying to find out what it wants to fetch, and would be a rather inefficient way to backfill a shallow clone. So I wonder how this fits into the larger picture.

Thanks.