attach does not work in Jupyter notebooks with any sage jupyter kernel (broken since 2017!)

[williamstein]

1. Make a file code.sage with code in it.
2. Type attach('code.sage'). There is a weird warning that has nothing to do with code.sage, but attach pretends to work.
3. Try to use something from code.sage -- it does not work.

Note that attach works fine in Sage worksheets and sage on the command line.

See https://cocalc.com/share/4a5f0542-5873-4eed-a85c-a18c706e8bcd/support/2018-06-12-sage-code/notebook.ipynb?viewer=share/

Attach fails in the same way using upstream plain jupyter, so this is a Sage bug or a problem with our kernel:

[williamstein]

Still broken, exactly in the same way, with SageMath version 8.8, Release Date: 2019-06-26.

NOTE: the load function works; it's just attach that doesn't... which is pretty serious, since that's an amazing command.

[AntoinePinardin]

Still not working for me with SageMath version 10.4.beta8. Did anyone find a way around this?

[williamstein]

This is an upstream bug in sage 10.3 -- sagemath/sage#26620

[williamstein]

Removing jupyter since this is a sage bug.