Precompilation doesn't finish and reconnecting to Binder

[BoundaryValueProblems]

In my Pluto notebook file, I have the following line in the very beginning:

using Markdown, InteractiveUtils, PlutoUI, Plots, LaTeXStrings, LinearAlgebra, FFTW

When I first connect this notebook file to binder, it got stuck at precompilation, and before finishing the precompilation stage, it is disconnected and always says the following:

A new server was started - this notebook session is no longer running.

Would you like to go back to the main menu?


[Go back](https://boundaryvalueproblems.github.io/EACHABook/)
[Stay here](https://boundaryvalueproblems.github.io/EACHABook/lecture02.html#)

How can I resolve this precompilation problem?

[fonsp]

Very strange! I tried your notebook now with binder, and it also failed. I notice that it disconnects while precompiling packages. I sometimes see a binder crash when the pod runs out of memory, but in this case the binder session remains active, you can still click the Pluto logo and go back to the main menu and start another notebook.

That means that the session suddenly got removed... but I don't think it is possible for an error to cause a session to be removed.

I launched a second notebook in parallel. The second notebook (1+1) works, but when the first notebook precompiles, both sessions are removed.

So I think that it is in fact a new session. This might be a Docker thing, were the crashed session is quitely swapped out for a new one.

[fonsp]

I think the conclusion is that the packages in this notebook require too much RAM to precompile, at least when precompilation happens in parallel. I can't really think of an easy to way to work around this, other than to try to use fewer heavy packages.

[BoundaryValueProblems]

@fonsp, thanks for your feedback. Is there any way to precompile these packages sequentially, not in parallel?

[fonsp]

Yes and no. Normally you could set https://docs.julialang.org/en/v1/manual/environment-variables/#JULIA_NUM_PRECOMPILE_TASKS to 1, but I don't think it is possible for you to set this for your notebook.

Binder on Pluto works different from normal binder projects, to make it possible to have the binder button on any notebook without setup. We just have one repository: https://github.com/fonsp/pluto-on-binder that is used by every notebook. This repo contains Pluto and some binder configuration to make it possible to use pluto on binder (which is not trivial).

The downside is that the binder does not have the precompilation cache ready for your notebooks. This would be possible if you had a binder repository just for your notebook(s). Then precompilation would happen once, during the binder build phase, and later launches would use the cache. But I'm not sure how to set this up.