Re: [PATCH v2 5/5] MyFirstObjectWalk: add stderr to pipe processing

[Kyle Lippincott <spectral@google.com>]

On Tue, Mar 19, 2024 at 12:23:15PM +0100, Dirk Gouders wrote:
> In the last chapter of this document, pipes are used in commands to
> filter out the first/last trace messages.  But according to git(1),
> trace messages are sent to stderr if GIT_TRACE is set to '1', so those
> commands do not produce the described results.
> 
> Fix this by redirecting stderr to stdout prior to the pipe operator
> to additionally connect stderr to stdin of the latter command.
> 
> Signed-off-by: Dirk Gouders <dirk@gouders.net>
> ---
>  Documentation/MyFirstObjectWalk.txt | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/MyFirstObjectWalk.txt b/Documentation/MyFirstObjectWalk.txt
> index 981dbf917b..2e6ae4d7fc 100644
> --- a/Documentation/MyFirstObjectWalk.txt
> +++ b/Documentation/MyFirstObjectWalk.txt
> @@ -847,7 +847,7 @@ those lines without having to recompile.
>  With only that change, run again (but save yourself some scrollback):
>  
>  ----
> -$ GIT_TRACE=1 ./bin-wrappers/git walken | head -n 10
> +$ GIT_TRACE=1 ./bin-wrappers/git walken 2>&1 | head -n 10
>  ----
>  
>  Take a look at the top commit with `git show` and the object ID you printed; it
> @@ -875,7 +875,7 @@ of the first handful:
>  
>  ----
>  $ make
> -$ GIT_TRACE=1 ./bin-wrappers git walken | tail -n 10
> +$ GIT_TRACE=1 ./bin-wrappers git walken 2>&1 | tail -n 10

I think there's a second issue here: this should be `./bin-wrappers/git`, right?

>  ----
>  
>  The last commit object given should have the same OID as the one we saw at the
> -- 
> 2.43.0
> 
>