Re: Testing for existence of a remote branch from a script

From: Theodore Ts'o <tytso@mit.edu>
Date: Jan 6, 2025, 16:36 UTC
Message-ID: <20250106163636.GH1284777@mit.edu>
In-Reply-To: <xmqqsepw0xk7.fsf@gitster.g>

On Mon, Jan 06, 2025 at 07:30:32AM -0800, Junio C Hamano wrote:

>  - Would it be useful if we introduced the ability to advertise
>    "custom capabilities" from the receiving end of the connection,
>    that does not affect how the rest of Git behaves at all?

So if enhancing the git server's functionality (either via git ls-remotes or some other operation) is on the table, one of the things that I would really love is some way of asking the question is "git commit <SHA hash>" in the remote repository reachable via some branch or git tag?", and optionally, "which git branch/tag should be fetched if the testing infrastructure wants to be able to test that specific git commit ID?"

I could solve that problem by doing a "git fetch", but in my case, the specific repository in question might not even be on the local client where the user is executing "gce-xfstests -c ext4/4k -g auto --repo stable-rc.git --commit 47c2f92131c4". (This command launches a VM which actually builds the kernel, and I'd like to be able to give immediate feedback about whether the command will fail due to the user typo'ing the git commit id without either waiting for the Google Cloud VM to launch and then fail, or doing a "git fetch" and determining whether the git commit is there. I might be executing this command while on a very slow networking link, such as when I'm in an airplane or on a cruise ship, and so the cost of doing the "git fetch" might be prohibitive.)

Thanks,

						- Ted