检测此错误很简单；当您尝试克隆以下仓库时，Git 会警告您：
$ git clone https://hostname/user/repo.git # Clone a repo > Cloning into 'repo'... > remote: Counting objects: 66179, done. > remote: Compressing objects: 100% (15587/15587), done. > remote: Total 66179 (delta 46985), reused 65596 (delta 46402) > Receiving objects: 100% (66179/66179), 51.66 MiB | 667 KiB/s, done. > Resolving deltas: 100% (46985/46985), done. > warning: remote HEAD refers to nonexistent ref, unable to checkout.要修复此错误，您需要成为 您的 GitHub Enterprise Server 实例 上仓库的管理员。 您需要更改仓库的默认分支。
之后，您可以从命令行获取所有可用分支的列表：
$ git branch -a # Lists ALL the branches > remotes/origin/awesome > remotes/origin/more-work > remotes/origin/new-master然后，您可以切换到新分支：
$ git checkout new-master # Create and checkout a tracking branch > Branch new-master set up to track remote branch new-master from origin. > Switched to a new branch 'new-master' > Switched to a new branch 'new-main'