And my Sourcetree(GUI for Git) and XCode sourcecontrol was weird as making warning.
or not working well.
As the searching result, It is caused by same name HEAD.
Check your repository. (in your .git repository folder)
$ git show-ref
There is two HEAD.
You can change the name using below commend.
$ git branch -m HEAD LocalHead
git branch -D HEAD
It is OK. You don't need to have HEAD repository on Local. (It made and work by itself in behind)