Bug Report

["Benjamin Sandeen" <benjaminsandeen2016@u.northwestern.edu>]

Today, I managed to create a duplicate branch in a git repository.  While
this may not be a bug per se, I do think that it is confusing and some way
of preventing such issues in the future may be helpful.

I first cloned the repository:

$ git clone https://github.com/CodeForChicago/superclass.git

Then, I created a new branch (or so I thought):

$ git checkout -b lesson_page

However, this branch has already existed for about 4 weeks, without my
knowledge.  I proceeded to do some work on the files it contained, and when
it came time to commit and push, and when I pushed, I got the following
message:

To https://github.com/CodeForChicago/superclass.git
 ! [rejected]        lesson_page -> lesson_page (non-fast-forward)
error: failed to push some refs to '
https://github.com/CodeForChicago/superclass.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

Given that I had believed that I had created the branch just a few hours
prior and was the first to attempt to push to it, this error was
consternating.

I may be wrong (I am aware that my understanding of git is limited), but I
believe that the git checkout -b command is simply supposed to create a new
branch and then switch to it (I'm not aware of any subtle behavior that goes
on behind the scenes if the "new" branch that the user is attempting to
create already exists).  This is why I said it "may not be a bug per se".
However, I expect most people who use git to expect this command to create a
new branch and then switch to it (this is what most sources online will tell
users to do to create a new branch), and as such, it would be extremely
beneficial if git were to, at the very least, alert the user to the conflict
in some way or another.

Thanks,
Ben

Lead Consultant, Northwestern University Information Technology
Research Assistant, Center for Interdisciplinary Exploration and Research in
Astrophysics at Northwestern University
Phsyics, Weinberg College of Arts and Sciences
Computer Science, Weinberg College of Arts and Sciences
Classics, Weinberg College of Arts and Sciences