# JuliaCall segmentation fault
**URL:** https://discourse.julialang.org/t/juliacall-segmentation-fault/80208
**Category:** General Usage
**Tags:** question
**Created:** [April 28, 2022, 12:31pm UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208 "2022-04-28T12:31:28Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@cjproud](https://discourse.julialang.org/u/cjproud)
#### Post date: [April 28, 2022, 12:31pm UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/1 "2022-04-28T12:31:28Z")
I’ve got a Julia module (which contains compiled Fortran code) which is called in Python using JuliaCall ([Guide · PythonCall & JuliaCall](https://cjdoris.github.io/PythonCall.jl/dev/juliacall/)), for example within a Python script:
```julia
from juliacall import Main as jl
jl.seval(using MyModule.jl)
```
When I then call this in a Python function:
```julia
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.
---
### Author:  [@cjproud](https://discourse.julialang.org/u/cjproud)
#### Post date: [April 29, 2022, 6:47am UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/2 "2022-04-29T06:47:54Z")
**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!
---
### Author:  [@cjdoris](https://discourse.julialang.org/u/cjdoris)
#### Post date: [April 29, 2022, 9:03pm UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/3 "2022-04-29T21:03:53Z")
Can you post a MWE please.
---
### Author:  [@cjproud](https://discourse.julialang.org/u/cjproud)
#### Post date: [April 30, 2022, 2:45am UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/4 "2022-04-30T02:45:55Z")
Sure, my Julia module looks like this:
```julia
module myModule
include("constants.jl")
end
```
where constants.jl is a simple dictionary:
```julia
molMassDict=Dict(
"La"=> 162.9085,
"Ce"=>172.1180,
)
```
I then call it in Python using:
```julia
#!/usr/bin/env python3
from juliacall import Main as jl
jl.seval("using myModule")
def test_julia_import():
print(jl.myModule.molMassDict)
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:
```julia
def django_view(request):
test_julia()
```
if I call test\_julia() within this, it instantly segfaults:
```julia
signal (11): Segmentation fault
in expression starting at none:0
Allocations: 6828442 (Pool: 6825828; Big: 2614); GC: 8
```
Seems like it’s Django specific?
---
### Author:  [@cjproud](https://discourse.julialang.org/u/cjproud)
#### Post date: [April 30, 2022, 3:25am UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/5 "2022-04-30T03:25:46Z")
@cjdoris this is possibly related?
> [@Pyjulia, Django, and segfaults](https://discourse.julialang.org/t/pyjulia-django-and-segfaults/25313/7):
>
> Just speculating, but would it help to use locks on Python-side so that only one thread at a time calls Julia?
---
### Author:  [@cjproud](https://discourse.julialang.org/u/cjproud)
#### Post date: [October 14, 2022, 9:47am UTC](https://discourse.julialang.org/t/juliacall-segmentation-fault/80208/6 "2022-10-14T09:47:06Z")
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](https://pypi.org/project/requests/)) on the Python side and Genie on the Julia side.