[~leijiang please use the workaround described in the comment prior to your request. Because there is an easy work around, this will not be investigated further by me.
Sorry this is not acceptable. The documentation in https://plugins.jenkins.io/git clearly states that the plugin will do the user and email configuration. Do you know how much hours developers waste to find out that something that should work out of the box needs workarounds? We have pipelines with more then 10 git checkouts where updates get pushed, so the pipeline scripts gets totally ugly.
It's sourced from a wiki page linked in the sidebar, everyone with an account can edit it. Users frequently contribute to that, and the changes are of varying quality. I'm sure Mark would appreciate your help in improving the quality of the documentation.
Michael D I'm happy to receive a pull request with automated tests that show the problem and a code change that fixes the tests. Thanks for your interest in helping the Jenkins project!
The workaround from above is not working though if only global git settings are used (not the per project behaviour). The according environment variables are not set if in that case.