notebook breaks in Pluto 0.18.0 while works in 0.17.3

[AbhimanyuAryan]

Packages install using PlutoPkg are not found SearchLight SearchLightSQLite

Video on notebook working in Pluto 0.17.3 (works)

p1@0.17.3.mp4

Video on notebook breaking in Pluto 0.18.0 (breaks)

p1@0.18.0.mp4

📝 Pluto notebook file: https://gist.github.com/AbhimanyuAryan/cb603f44c4186eeb5bf310204a81a496 (it is little long that was best I could do to strip it down. All components are dependent on each other)

Start breaking near this line where SearchLight is being used

[fonsp]

Packages install using PlutoPkg are not found SearchLight SearchLightSQLite

What does this mean?

Thanks for providing the video and the notebook file, but what is the problem exactly?

• What is broken?
• How can you tell?
• Why should it not be broken?
• What have you tried already?

[fonsp]

It looks like the notebook is relying on the order of side effects. For example, these three cells:

filename = "hello"

write(filename, "world!")

read(filename, String) == "world!"

are not guaranteed to run top to bottom, because we run cells in "topological order" instead. Pluto might run this notebook in the order 1, 3, 2, because this respects all variable links.

You can fix this by creating dummy variables, like you are already doing in some places:

filename = "hello"

written = write(filename, "world!")

written; read(filename, String) == "world!"

Note that now there is an explicit link 2 -> 3, meaning that 2 must run before 3. Just referencing filename in the third cell is not enough.

An example in your notebook:
Cell A: https://gist.github.com/AbhimanyuAryan/cb603f44c4186eeb5bf310204a81a496#file-pluto_bug-jl-L660
Cell B: https://gist.github.com/AbhimanyuAryan/cb603f44c4186eeb5bf310204a81a496#file-pluto_bug-jl-L685

Because of side effects (writing to the /migrations folder), B must run after A, but there is no variable linking the two. They both depend on db, but this does not define their relative order.

There are some more hidden dependencies between cells in the notebook, like these four cells: https://gist.github.com/AbhimanyuAryan/cb603f44c4186eeb5bf310204a81a496#file-pluto_bug-jl-L608-L640 I recommend putting these into a single cell.