JuliaCall segmentation fault

I’ve got a Julia module (which contains compiled Fortran code) which is called in Python using JuliaCall (Guide · PythonCall & JuliaCall), for example within a Python script:

from juliacall import Main as jl
jl.seval(using MyModule.jl)

When I then call this in a Python function:

def mypythonfunction():
    Output = jl.MyModule.calc_something(args)

I get an instant segmentation fault (11), any ideas?

Edit: A note, this fails even when not using the compiled Fortran code and calling straight Julia code.

Update, this is also the same using PyJulia. As soon as I import the module in the global scope and try call it within a function it instantly segfaults.

I am at a loss!

Can you post a MWE please.

Sure, my Julia module looks like this:

module myModule

where constants.jl is a simple dictionary:

    "La"=> 162.9085,

I then call it in Python using:

#!/usr/bin/env python3

from juliacall import Main as jl
jl.seval("using myModule")

def test_julia_import():


Interestingly this MWE works no problem. The problem arises when I try to do this inside a Django (I’m not sure if you’re familiar with Django but it’s a Web Dev framework) view. A Django view is similarly a Python function, for example:

def django_view(request):

if I call test_julia() within this, it instantly segfaults:

signal (11): Segmentation fault
in expression starting at none:0
Allocations: 6828442 (Pool: 6825828; Big: 2614); GC: 8

Seems like it’s Django specific?

@cjdoris this is possibly related?

In case anyone comes here looking for answers, I’ve ended up moving the Julia code to it’s own microservice. The communication between Python and Julia is handled via requests (requests · PyPI) on the Python side and Genie on the Julia side.