On Tue, Jul 30, 2024 at 1:44 AM Sayooj Surendran
[off-list ref] wrote:

Noticed that the output of git checkout command is going to stderr
channel. Is this an intended behaviour?

Yes, it is intentional. Git's Documentation/CodingGuidelines has this to say:

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Program Output

 We make a distinction between a Git command's primary output and
 output which is merely chatty feedback (for instance, status
 messages, running transcript, or progress display), as well as error
 messages. Roughly speaking, a Git command's primary output is that
 which one might want to capture to a file or send down a pipe; its
 chatty output should not interfere with these use-cases.

 As such, primary output should be sent to the standard output stream
 (stdout), and chatty output should be sent to the standard error
 stream (stderr). Examples of commands which produce primary output
 include `git log`, `git show`, and `git branch --list` which generate
 output on the stdout stream.

 Not all Git commands have primary output; this is often true of
 commands whose main function is to perform an action. Some action
 commands are silent, whereas others are chatty. An example of a
 chatty action commands is `git clone` with its "Cloning into
 '<path>'..." and "Checking connectivity..." status messages which it
 sends to the stderr stream.

 Error messages from Git commands should always be sent to the stderr
 stream.

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