Question: A co-worker and I have been working on the same branch for a week, constantly pushing/pulling changes and all of a sudden today, I hit 'pull' to see if there were any changes I needed to pull and I got an error.

This is in sourcetree by the way. The error was this:

```
git -c diff.mnemonicprefix=false -c core.quotepath=false fetch origin
error: cannot lock ref 'refs/remotes/origin/angular_removal': unable to resolve reference 'refs/remotes/origin/angular_removal': reference broken
From https://bitbucket.org/colossus
 ! [new branch]        angular_removal -> origin/angular_removal  (unable to update local ref)

```

I'm in sourcetree, which has a terminal built in, but I can't seem to find a resolution here.

Answer: 
I was able to get this fixed by deleted all the items in the `.git/packed-refs` file.

Then I just did a git pull in terminal to get all the references/code from the remote.
Case 1: Let check branchs from git-server if they are duplicate or not.

```
Example: two branchs below are duplicate:

- upper_with_lower
- UPPER_with_lower

---> Let consider removing one of them.

```

Case 2: The branch you are pushing are duplicate with other branch.