`Failed to find Base.active_repl_backend.ast_transforms` in jupyter notebooks

[lgoettgens]

With the exact startup file as the example in the README.md, I get the following output every time I execute the first cell (after kernel restart) in a jupyter notebook.

�[33m�[1m┌ �[22m�[39m�[33m�[1mWarning: �[22m�[39mFailed to find Base.active_repl_backend.ast_transforms
�[33m�[1m└ �[22m�[39m�[90m@ BasicAutoloads ~/.julia/packages/BasicAutoloads/WpUQa/src/BasicAutoloads.jl:108�[39m

or without formatting:

┌ Warning: Failed to find Base.active_repl_backend.ast_transforms
└ @ BasicAutoloads ~/.julia/packages/BasicAutoloads/WpUQa/src/BasicAutoloads.jl:108

This happens both on a julia 1.10.5 and a julia 1.11.1 kernel.

To skip loading of BasicAutoloads for jupyter notebooks, I changed the first line of my startup file to

if Base.isinteractive() && !isdefined(Main, :IJulia)

but this does not change anything about the above issue.

Do you have an idea how to make BasicAutoloads either work with jupyter notebooks or skip loading it at all?

[LilithHafner]

I have been unable to launch a jupyter notebook successfully and cannot reproduce this with Pluto.

I'll continue investigating.

[LilithHafner]

I've now successfully launched a jupyter notebook with the startup file from the README here. I still can't reproduce this warning. Would you provide more detailed reproduction instructions? e.g. how are IJulia/jupyter installed? How are you launching the notebook?

[lgoettgens]

I tried to do everything again as a few days ago, but write them down step by step, and suddenly the error vanished. Then I went back to work and have it again.

Steps to reproduce:

• Install julia 1.10.5 via juliaup on linux.
• Put the startup.jl from the README in you .julia/config/ folder.
• Install IJulia using Pkg.add("IJulia") to the global environment. This for me installed v1.25.0.
• Build a jupyter kernel using Pkg.build("IJulia")
• Start a jupyter server using using IJulia; notebook().
• Via the jupyter web GUI, reate a new notebook in some random folder (that does not contain a Project.toml nor a Manifest.toml).
• Write sleep(3) in the first code cell and execute it. (In my case, I load some package that needs 10+ seconds to load, but this is a pure julia mwe. But for me it is using Oscar.)
• Using the jupyter web GUI, press Kernel > Restart Kernel and Run All Cells...
• The warning appears

[LilithHafner]

I followed those steps and successfully reproduced the warning. Thanks!

[LilithHafner]

IJulia sets is_interactive at

https://github.com/JuliaLang/IJulia.jl/blob/0db1fa2c6b3f04d43a18830c631a1e46851908b6/src/kernel.jl#L44

even through there is no REPL. Consequently the startup file thinks that there is a REPL and launches BasicAutoloads which fails to hook into the REPL because there is not REPL. BasicAutoloads prints a warning because register_autoloads was called and did not successfully register any autoloads. Switching isinteractive() to stdin isa Base.TTY in your startup.jl should remove this warning.

Another, much harder, fix would be to create a package extension for BasicAutoloads & IJulia.

[danielwe]

I get the same warning in the REPL, but in my case it's just that I'm testing some slow startup.jl ideas that increase the startup time a lot, so BasicAutoloads times out waiting for active_repl_backend.

• Are you open to bumping the max waiting time a bit? Looks like it's currently 1 second.
• Should the warning be reworded to clarify that autoloads failed to register, and that this is a timeout issue that might be caused by excessive startup time?

[danielwe]

Moving register_autoloads to the bottom of my startup.jl seems to have fixed the issue, so maybe suggest that in the README/docstring, rather than increasing the timeout.

[LilithHafner]

@danielwe, those are good ideas, thanks! I've implemented and released them. See #17 and release v1.0.3.

[LilithHafner]

Another workaround is to check for haskey(ENV, "JPY_SESSION_NAME") in startup.jl