Traceback details when using include()

billtubbs · June 27, 2020, 7:11pm

I’m a beginner here so might be missing something, but I’ve noticed that when I try to include a file that has a bug in it (into a Jupyter notebook), the traceback details are not that helpful because they don’t show the line number on the included file where the error occurred.

Example (file “CartPoleBTEnv.jl” has a syntax error on line 165):

Code in Jupyter cell:

include("CartPoleBTEnv.jl")

Cell output:

syntax: extra token "not" after end of expression

Stacktrace:
 [1] include at ./boot.jl:326 [inlined]
 [2] include_relative(::Module, ::String) at ./loading.jl:1038
 [3] include(::Module, ::String) at ./sysimg.jl:29
 [4] include(::String) at ./client.jl:403
 [5] top-level scope at In[1]:1

Here is the traceback detail if I run the offending file from the command line:

ERROR: LoadError: syntax: extra token "not" after end of expression
Stacktrace:
[1] include at ./boot.jl:326 [inlined]
[2] include_relative(::Module, ::String) at ./loading.jl:1038
[3] include(::Module, ::String) at ./sysimg.jl:29
[4] exec_options(::Base.JLOptions) at ./client.jl:267
[5] _start() at ./client.jl:436
in expression starting at /Users/billtubbs/cartpole/CartPoleBTEnv.jl:165

oheil · June 28, 2020, 8:59am

I tried it and I wasn’t able to reproduce your finding.
I get (near) exactly the same error in a jupyter notebook as in a plain REPL.
Julia 1.4.1, Windows 10, IJulia and Conda/Jupyter latest version/newly installed here.

billtubbs · June 28, 2020, 6:07pm

Thanks @oheil. My versions:

Julia: 1.1.1
Jupyter notebook server: 6.0.3
Running on Python: 3.7.7
Browser: Safari 13.1.1
OS: Mac OS X 10.14.6

Here is a setup which I can reproduce:

File test_error.jl in same folder as notebook contains:

x = 1 
x not 1

Screenshot of Jupyter notebook:

I’ll try updating my Julia. I only installed it yesterday using conda install -c conda-forge julia and it gave me 1.1.1. I will see if I can find a more recent version.

Here is the console output:

(julia) Bills-Mac-mini-2:cartpole billtubbs$ julia test_error.jl 
ERROR: LoadError: syntax: extra token "not" after end of expression
Stacktrace:
 [1] include at ./boot.jl:326 [inlined]
 [2] include_relative(::Module, ::String) at ./loading.jl:1038
 [3] include(::Module, ::String) at ./sysimg.jl:29
 [4] exec_options(::Base.JLOptions) at ./client.jl:267
 [5] _start() at ./client.jl:436
in expression starting at /Users/billtubbs/cartpole/test_error.jl:2
(julia) Bills-Mac-mini-2:cartpole billtubbs$ which julia
/anaconda3/envs/julia/bin/julia

Note: All that is missing from the Jupyter output is the last line:

in expression starting at /Users/billtubbs/cartpole/test_error.jl:2

Can you confirm you see that in your Jupyter notebook?

Other than that could it be a problem with my Jupyter install?

dpsanders · June 28, 2020, 6:44pm

You should download the latest stable version of Julia (1.4.2) directly from

Alternatively you can install it on a Mac using homebrew, if you have that installed.

Ralph_Smith · June 28, 2020, 6:47pm

FWIW I see the same problem as the OP, using Julia v1.4.1 on Linux with IJulia v1.21.2. Also using the Jupyter console. Outstanding issue:
https://github.com/JuliaLang/IJulia.jl/issues/883

oheil · June 28, 2020, 6:57pm

Confirmed. Your example can be reproduced on my setup.
So, issue above still open.

billtubbs · June 28, 2020, 7:49pm

Thanks. If I do that can I still put it in a conda environment?

billtubbs · June 28, 2020, 7:59pm

Okay so if it’s not just me, then is this maybe normal behaviour in a jupyter notebook?

Note, if the error occurs in the notebook, you don’t get any more useful information:

Dumb question: What does include() actually do? Does it effectively move the code into the notebook and then compile it? If so, why would we expect a reference to a line in the original file?