Binder correctly pulls the data for a branch, but git thinks it is in the master branch

Bug description

When binder launches from a github branch, it gets the correct data for that branch. If you launch a Terminal window, git does not reflect that.

git branch
* master

Expected behaviour

In my example, I used the development branch. I expected git branch to report “development”.

Actual behaviour

See bug description, above.

How to reproduce

This is the contents of README.md in my development branch:

bindertest

Test of using branch in binder

development branch

1. Click on the launch binder badge.
2. After jupyterlab shows up, launch Terminal panel
3. In Terminal, git branch
4. Reports “* master”, expect “* development”

Your personal set up

Not relevant

• OS: Using Mac, but I don’t think that matters
• Version:

jupyterhub --version
1.1.0

• Configuration: N/A

[manics]

I wonder if it’s related to

• --no-checkout https://github.com/jupyter/repo2docker/blob/8bbced7ded5a21b581f1f3846ffc9f87944ba799/repo2docker/contentproviders/git.py#L31
• git reset --hard https://github.com/jupyter/repo2docker/blob/8bbced7ded5a21b581f1f3846ffc9f87944ba799/repo2docker/contentproviders/git.py#L55

[manics]

It’s to do with submodules

• https://github.com/jupyter/repo2docker/pull/809
• https://github.com/jupyterhub/binderhub/issues/997

According to https://github.com/jupyterhub/nbgitpuller/issues/142 it’s possible to set the upstream git branch after cloning which might resolve this issue.