With this error message Gerrit rejects to push a commit for code review if the specified target branch does not exist.

To push a change for code review the commit has to be pushed to the project’s magical refs/for/'branch' ref (for details have a look at Create Changes). If you specify a non-existing branch in the refs/for/'branch' ref the push fails with the error message branch … not found.

To fix this problem verify

  • that the branch name in the push specification is typed correctly (case sensitive) and

  • that the branch really exists for this project (in the Gerrit WebUI go to Projects > List and browse your project, then click on Branches to see all existing branches).

If it was your intention to create a new branch you can either

  • bypass code review on push as explained here or

  • create the new branch in the Gerrit WebUI before pushing (go to Projects > List and browse your project, in the Branches tab you can then create a new branch).

Please note that you need to be granted the Create reference access to create new branches.