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

[fm75]

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:
  bash jupyterhub --version 1.1.0
• Configuration: N/A

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[betatim]

Could this be because both development and master are the same commit 815012fb283e933b1a56bc8b777abbd3df5ee234? What happens if you add a commit to your development branch and then start a new binder?

edit: they aren't the same commit.

Need to think about why/how git branch shows "the wrong" branch name.

[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

[betatim]

Does anyone remember why we do such "weird" things on checkout instead of a more standard workflow?

[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.