Autocomplete problem in output cell.

[garazha-ilya]

Autocompletion works well, but errors inside output cell occured every time.

1. The output of versioninfo() :

Julia Version 1.9.3
Commit bed2cd540a1 (2023-08-24 14:43 UTC)
Build Info:
Official https://julialang.org/ release
Platform Info:
OS: Linux (x86_64-linux-gnu)
CPU: 8 × 11th Gen Intel(R) Core(TM) i7-11370H @ 3.30GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-14.0.6 (ORCJIT, tigerlake)
Threads: 1 on 8 virtual cores

2. How you installed Julia

wget https://julialang-s3.julialang.org/bin/linux/x64/1.9/julia-1.9.4-linux-x86_64.tar.gz
tar zxvf julia-1.9.4-linux-x86_64.tar.gz

3. A minimal working example (MWE), also known as a minimum reproducible example:
   using Pkg; Pkg.add("IJulia"); using IJulia; notebook()

Settings -> Settings Editor -> Code Completion -> Enable autocompletion -> true

In first evaluation (Shift + Enter) everything works fine, but after second evaluation of the same code occurs error message:

If autocompletion is disabled, then everything works normal.

KERNEL EXCEPTION
BoundsError: attempt to access empty String at index [1:40]

Stacktrace:
 [1] checkbounds
   @ ./strings/basic.jl:216 [inlined]
 [2] getindex(s::String, r::UnitRange{Int64})
   @ Base ./strings/string.jl:276
 [3] complete_request(socket::ZMQ.Socket, msg::Msg)
   @ IJulia ~/.julia/packages/IJulia/Vo51o/src/handlers.jl:115
 [4] #invokelatest#2
   @ ./essentials.jl:819 [inlined]
 [5] invokelatest
   @ ./essentials.jl:816 [inlined]
 [6] eventloop(socket::ZMQ.Socket)
   @ IJulia ~/.julia/packages/IJulia/Vo51o/src/eventloop.jl:8
 [7] (::IJulia.var"#15#18")()
   @ IJulia ./task.jl:514

[stevengj]

My version of Jupyter doesn't have a "Code completion" option in the "Settings" menu:

How did you get this? I just did a fresh install from Conda.

[stevengj]

It sounds like Jupyter might sending IJulia an invalid completion request message on your machine. You could verify this by setting IJulia.verbose = true, which causes every message from Jupyter to be printed in the terminal. Look for something like:

RECEIVED IPython Msg [ idents b9b9f847-93ce-492c-a345-333b8a8ec0e0 ] {
  parent_header = Dict{String, Any}(),
  header = Dict{String, Any}("msg_id" => ....),
  metadata = Dict{String, Any}(),
  content = Dict{String, Any}("cursor_pos" => ...., "code" => ".....")
}

[garazha-ilya]

My version of Jupyter doesn't have a "Code completion" option in the "Settings" menu: How did you get this? I just did a fresh install from Conda.

On main menu:

I install Jupyter notebook via Ijulia instructions:
https://github.com/JuliaLang/IJulia.jl -> Quick start -> using IJulia; notebook()

[garazha-ilya]

After adding something stranger happens:

Now, in the end of the line, after pressing Tab, displays a lot of completion.
Also, I don't understand, where the Terminal and command IJulia.verbose = true should be started and typed in?

[JamesWrigley]

I didn't hit that specific error, but with luck it and another error will be fixed by #1159. But something seems to be broken with string macros:

In the GIF I type l and the completions for l pop up. Selecting lastindex works, but if I go lower and select lazy" then Jupyter appears to ignore that entry and jumps to lcm. And if I select lcm it jumps to the entry below that, ldexp.

Here's another example with s" where there's consistently an offset from the selected entry:

From the logs I can see that Jupyter never sends an inspect_request for string macros whereas it does for any other completion option, so I wonder if it's an upstream bug somewhere.