threads / discuss / 51783

Retrieve version-string on shallow clone

Subject: Retrieve version-string on shallow clone

## tl;dr

3 messages between Sep 1, 2019 and Sep 2, 2019.

replies: 2people: 3as markdown or json

Reino Wijnsma· Sep 1, 2019, 11:07 UTC · lore

Hello git@vger.kernel.org,

Two days ago I started https://github.com/mstorsjo/fdk-aac/issues/107, asking how to retrieve the fdk-aac version-string on a shallow clone. My question was of course not fdk-aac related, so Martin Storsjö suggested I'd try here. It basicly comes down to this:

git clone https://github.com/mstorsjo/fdk-aac.git [...]

git describe --tags v2.0.0-185-gcc5c85d

git clone --depth 1 https://github.com/mstorsjo/fdk-aac.git

git describe --tags fatal: No names found, cannot describe anything.

The tags get lost while doing a shallow clone. I'm not an expert git user, so I was wondering if anyone could tell what my options are here. I'd figure one of these options would be to clone everything from tag v2.0.0 onward, but if so how would I do that? As another option I was thinking; maybe it's possible to do git describe --tags on the remote repo?

Thanks!

-- Reino

Philip Oakley· Sep 2, 2019, 15:52 UTC · re: Reino Wijnsma · lore

Re: Retrieve version-string on shallow clone

Hi Reino

On 01/09/2019 12:07, Reino Wijnsma wrote:

Show 21 quoted lines

> Hello git@vger.kernel.org,
>
> Two days ago I started https://github.com/mstorsjo/fdk-aac/issues/107, asking how to retrieve the fdk-aac version-string on a shallow clone.
> My question was of course not fdk-aac related, so Martin Storsjö suggested I'd try here. It basicly comes down to this:
>
> git clone https://github.com/mstorsjo/fdk-aac.git
> [...]
>
> git describe --tags
> v2.0.0-185-gcc5c85d
>
> git clone --depth 1 https://github.com/mstorsjo/fdk-aac.git
>
> git describe --tags
> fatal: No names found, cannot describe anything.
>
> The tags get lost while doing a shallow clone.
> I'm not an expert git user, so I was wondering if anyone could tell what my options are here.
> I'd figure one of these options would be to clone everything from tag v2.0.0 onward, but if so how would I do that?
> As another option I was thinking; maybe it's possible to do git describe --tags on the remote repo?
>

This is most likely a mental model problem.

If you only have a depth = 1 level clone, then there is no history available locally to use from which to describe almost anything. Even if you had all the tags (without the actual commits they tagged) you still don't have that history upon which to describe them.

Start by getting a bit more history depth, then see if you need to fetch some of the tags (or at least any specific tags of interest).

Philip

Jeff King· Sep 2, 2019, 15:54 UTC · re: Reino Wijnsma · lore

Re: Retrieve version-string on shallow clone

On Sun, Sep 01, 2019 at 01:07:44PM +0200, Reino Wijnsma wrote:

Show 12 quoted lines

> git clone https://github.com/mstorsjo/fdk-aac.git
> [...]
> 
> git describe --tags
> v2.0.0-185-gcc5c85d
> 
> git clone --depth 1 https://github.com/mstorsjo/fdk-aac.git
> 
> git describe --tags
> fatal: No names found, cannot describe anything.
> 
> The tags get lost while doing a shallow clone.

Right. As noted elsewhere in the thread, this is the expected behavior of Git. But what you want is perfectly reasonable; there's just not a good way to do it yet.

> I'd figure one of these options would be to clone everything from tag
> v2.0.0 onward, but if so how would I do that?

I don't think there's a good way to do this. But I also think it's not quite what you want, as you'd end up transferring a lot of extra data (and deeper shallow fetches load the server more, as we can't use reachability bitmaps, and we have to do extra on-the-fly delta compression).

> As another option I was thinking; maybe it's possible to do git
> describe --tags on the remote repo?

This seems like it's more directly what you want, and doesn't have a lot of downsides. There's no way to trigger this within Git's protocols. If it's an ssh server you control, you can of course run git-describe yourself on the server. For a hosting site like GitHub, you'd need support from the host's non-Git API. I don't _think_ anything like that exists right now in GitHub's API, though.

-Peff