Requirement: Git branch merge
Git Merge: A branch merge is performed locally with Git Merge, and you want to push it to Gerrit to review the repository. However, when you commit it, you can say:

! [remote rejected] HEAD -> refs/for/dev (no new changes)

No new changes have been made to the system, but the changes are linear. Gerrit will not allow you to submit a review if you don’t have a new commit. If you don’t have a new commit, Gerrit will not allow you to submit a review.
Method 1: When git merge, add the –no-ff parameter to make it a new commit so that it can commit ~ (but the generated Gerrit change does not see the change).
Method 2: Push directly into the remote library without going through Gerrit. (Not recommended)