Command line git 2.51.0 (released 18 Aug 2025) has dropped support for the "git whatchanged" command.  The git client plugin 6.3.0 and earlier uses "git whatchanged" to generate changelogs.

A freestyle job on a controller with command line git 2.51.0 silently fails to generate the changelog. I created the job and configured a git repository to be used in the job and ran the job. The changelog for the first run was empty as expected. I submitted additional changes to the git repository and ran the job again. The changelog was not displayed when git 2.51.0 was installed on the controller. When earlier versions of command line git are installed on the controller, the changelog is displayed correctly.

Workarounds include configuring the job to use JGit instead of command line git or downgrading the version of command line git to an older version or install the pre-release git client plugin by downloading [^git-client-6.3.1-rc3772.9999864ed11a_.hpi], renaming it as git-client.jpi, copying it into the Jenkins plugins directory, and restarting Jenkins.

Users running command line git 2.51.0 from a shell will receive the message

'git whatchanged' is nominated for removal.
If you still use this command, please add an extra
option, '--i-still-use-this', on the command line
and let us know you still use it by sending an e-mail
to <git@vger.kernel.org>.  Thanks.
fatal: refusing to run without --i-still-use-this
 

 
As reported in JENKINS-76009, there are plugins that generate the changelog on the agent, so any agent that is upgraded to CLI git 2.51.0 may see failures as well.