Cell that starts with %%time does not report errors

[vincent-163]

🐛 Bug

Running a new notebook with two cells via papermill: (assuming results.json does not exist)

%%time
# cell 1
with open('results.json') as f:
    results = json.load(f)

print(results)

Gives

NameError: name 'results' is not defined`

for the second cell. The first cell's error is silently ignored without any warnings, and the only clue is that the cell's time is not reported as well.

If %%time is removed from the first cell, the error is reported properly and the execution is interrupted at the first cell:

FileNotFoundError: [Errno 2] No such file or directory: 'results.json'

[zmbc]

This is actually an upstream issue in IPython: https://github.com/ipython/ipython/issues/12971

[MSeal]

I put a comment on that thread, it is indeed a magic implementation issue and not a notebook or papermill specific control point.