Brian Duggan

How do other kernels do it?

Interesting. Is there a use case for this? If not, preventing it seems like the most straightforward fix.

Oh, I see. So, in this case the desired behavior would be for it to work like any other sub, i.e. not have any interactions with the command-line world

Interesting. For the bug, perhaps this will address it: 54163f422c5caa7fcd3199cd07b0e033a9896ef3 since there appears to be duplicate `WHAT`s in the output. I can confirm that Tab completion is not working in...

Oh, I see it is not just binder, but JupyterLab. Yes, I am able to reproduce this. There seems to have been some sort of backwards-incompatible change to the protocol;...

Interestingly, this seems specific to JupyterLab -- completions work fine in a regular notebook or a terminal console (and the kernel is sending the same response in all those cases).

I've started a grammar :) https://github.com/bduggan/p6-protobuf

Thanks @taboege -- no, I hadn't seen that!