Error: build failed for imageName

[lukedeo]

@freeman-lab @andrewosh it seems that every Dockerfile I throw at MyBinder, including this repo, results in an error that looks like:

Successfully built 44795ab92c04
could not build image binder-project-example-dockerfile: Error: build failed for imageName: binder-project-example-dockerfile
registering template for binder-project-example-dockerfile

Any ideas as to what could be going on?