hitting run on a notebook too soon after compute on the page has been enabled causes execute to fail

[stevejpurves]

Describe the bug

context
When I press the power button on a notebook and the run button becomes available, and I quickly press it.

expectation
I expected the cells to execute and they appear to as busy cursors appear, but then execution never completes

bug
But instead execution never completes, and it looks like thebe thinks the cells were already executed -- but that occured too fast to be possible.

problem
This is a problem as people think the execution is happening or has hung

Reproduce the bug

1. go to https://simpeg.xyz/tle-finitevolume/all-together-now
2. press the power button
3. click run immedaitely after is appear

contrast this to:

1. go to https://simpeg.xyz/tle-finitevolume/all-together-now
2. press the power button
3. wait a few seconds
4. click run immediately after it appears

List your environment

No response

[stevejpurves]

I think this could be down to a silent return in the execute call (maybe because of an exception being eaten or someone) in the case where the session/kernel has not yet been attached.