Re: [PATCH] t0213: skip ancestry tests under user-mode emulation

From: Weijie Yuan <wy@wyuan.org>
Date: Jul 21, 2026, 18:06 UTC
Message-ID: <al-1JkcH91aW6VWM@wyuan.org>
In-Reply-To: <pull.2168.git.1783359242130.gitgitgadget@gmail.com>

On Mon, Jul 06, 2026 at 05:34:01PM +0000, Jamie Magee via GitGitGadget wrote:

Show 16 quoted lines

> From: Jamie Magee <jamie.magee@gmail.com>
> 
> The tests added in 3c8c638df6 (t0213: add trace2 cmd_ancestry tests,
> 2026-02-13) expect the cmd_ancestry event to name "test-tool" and
> "git". On Linux those names come from the "comm" field of
> /proc/<pid>/stat. Under user-mode emulation (e.g. qemu-user) /proc
> reports the emulator ("qemu-riscv64") instead, so the event is still
> emitted, the TRACE2_ANCESTRY probe enables the tests, and tests 2-5
> fail even though they pass on native riscv64.
> 
> Require the probe to see "test-tool" in the ancestry of a test-tool
> spawned from test-tool, so the tests skip when the names are unreliable.
> 
> Cc: Matthew John Cheetham <mjcheetham@outlook.com>
> Signed-off-by: Jamie Magee <jamie.magee@gmail.com>
> ---

Very sorry to say something completely outside the patch.

But may I ask what's the point of writting the line started with "Cc:"? I know that Linux kernel has something about writting Cc in the commit message, while I don't see much from Git's documentation about trailers, including MyFirstContribution and SubmittingPatches. Although I know that "git send-email" and "git interpret-trailers" could use "Cc:", I still wonder whether using this trailer is encouraged or not. If so, adding some decriptions about it would be nice, I guess, since I was confused when reading kernel docs about using Cc trailers in the commit message sometime ago.

Sorry in advance if I missed any context.

Thanks very much.