Build stuck on a running jupyter notebook server

[leouieda]

I was trying to fix the password problem and I naively put RUN jupyter notebook --NotebookApp.token='' (as suggested by @lgpage on gitter) in my Dockerfile. Now my build has a running jupyter notebook server and won't finish, shutdown or restart: http://mybinder.org/status/pinga-lab/nmo-tutorial

When I click on rebuild I get the following in the log:

starting build for URL: https://github.com/pinga-lab/nmo-tutorial 
already building pinga-lab-nmo-tutorial -- not rebuilding

I tried pushing new code and then triggering a rebuild but with no success.

Is there any way to tell binder to abort the build?