Help debugging "Output data no longer available, please reevaluate this cell"

[venkatd]

Hi all!

I will intermittently get errors like so:

What typically causes these errors? I am trying to come up with a reproduction, but it doesn't seem to happen consistently. Sometimes re-evaluating works, sometimes refreshing the browser tab works, sometimes it doesn't.

I read a separate discussion (#1395) on this error but I don't believe I'm doing anything fancy with processes.

[jonatanklosko]

@venkatd on the screenshot the cell status is Aborted, so I expect the runtime is restarted or terminated? Certain outputs (including Kino.Tree) have data stored in the runtime, hence they become unavailable once the runtime is gone.

[venkatd]

@jonatanklosko Aside from clicking "reconnect and setup" what other things could cause it to get aborted or restarted?

We are not explicitly aborting the runtime so I will need to investigate what is causing the runtime to restart/terminate.

Thanks!

[jonatanklosko]

The runtime is a separate Elixir node, so it could terminate with OOM, NIF segfault, or something like that. It could also be that the runtime is still up, but the evaluation process terminates, for example if you start_link something and that process terminates. In both cases we show an error snackbar.

Another way for a cell to be marked as aborted is stopping it while it's evaluating, but I assume that's not the case, since you wouldn't have the output in the first place.