Is there any way we can parametrise this kernel restart behaviour?

[jamesowers-cohere]

The line:

bash_kernel/bash_kernel/kernel.py

Line 219 in f07a743

output = self.bashwrapper.child.before + 'Restarting Bash'

means that, upon error, the kernel is restarted. This means that, in the context of executing all cells in a notebook from start to finish, the execution will continue after a cell is executed which contained an error.

I would love to be able to disable this behaviour i.e. make it such that execution stops upon first failure.

Is there any easy way to make this happen currently, or would it be easy to add this feature (and demonstrate usage via the README?).

[takluyver]

What code are you putting in a cell that leads to this?

bash_kernel is running a bash interactive session in a pseudoterminal. Most errors in bash code don't exit the shell, which is what would lead to this branch. Rather, they spit out an error message and then return to the prompt, where you need to check $? to know in a machine-readable way if the last command failed. This goes even for things like syntax errors which would be fatal in a normal programming environment - they don't kill the shell. So errors in general are already handled in bash_kernel.

I'm not saying nothing should change in this code path, but I want to understand what's happening properly before trying to fix it - it might be that it's better fixed another way.

[jamesowers-cohere]

For context, I'm using the kernel via Quarto.

My issue occurs whenever a command is issued that emits a nonzero status - I imagine that this is partially due to how quarto handles the process. The desired behaviour is that if any of the cells in the notebook fail then the quarto process should fail. However, what happens is that the bash_kernel restarts and execution continues.

[jamesowers-cohere]

This fully fleshes out the problem and the use case: https://github.com/orgs/quarto-dev/discussions/4634#discussioncomment-14840326