# Crash: illegal instruction 4, StackOverflowError, or freeze
**URL:** https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754
**Category:** General Usage
**Tags:** stackoverflow, crash, illegal-instruction
**Created:** [July 8, 2024, 7:41am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754 "2024-07-08T07:41:43Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@ryofurue](https://discourse.julialang.org/u/ryofurue)
#### Post date: [July 8, 2024, 7:41am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/1 "2024-07-08T07:41:43Z")
[**Edit 2:** I’ve just posted a small program that reproduces this error in a separate message below.]
Can someone give me advice as to how to proceed when Julia crashes?
At first, I got the following error
```julia
[8865] signal (4.1): Illegal instruction: 4
in expression starting at none:0
_os_unfair_lock_recursive_abort at /usr/lib/system/libsystem_platform.dylib (unknown line)
_os_unfair_lock_lock_slow at /usr/lib/system/libsystem_platform.dylib (unknown line)
Allocations: 10807566 (Pool: 10799892; Big: 7674); GC: 21
fish: Job 1, 'julia ctw-superp-001.jl' terminated by signal SIGTRAP (Trace or breakpoint trap)
```
within a call to a `Makie` function.
My julia interpreter was up to date (1.10.4, because I keep it updated with `juliaup update`), but the packages weren’t. So, I entered the package manager and updated everything.
Then, I got
```julia
ERROR: LoadError: StackOverflowError:
in expression starting at . . .
```
which points to the line of my program that calls the function that calls the `Makie` function that crashes.
I next I inserted some print statements (`display` or `@show`) before the function call which crashes to try to look at the arrays I send to the function. Then, the program freezes.
What’s the best way to proceed?
**Edit:** My code doesn’t involve any recursive calls. A print statement before the external crashing function prints on the screen but a call to `error()` after the crashing function is never reached. (Unless there were a callback from the crashing function to my code, there cannot be recursion involving my code.)
---
### Author:  [@abraemer](https://discourse.julialang.org/u/abraemer)
#### Post date: [July 8, 2024, 7:45am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/2 "2024-07-08T07:45:42Z")
> [@ryofurue](#):
>
> What’s the best way to proceed?
Reduce your code as much as you can without making the crash disappear and post it here 🙂
Are you doing any recursive calls yourself or do you think that this error occurs inside Makie.jl? Does it still happen when you remove all plotting functions?
---
### Author:  [@ryofurue](https://discourse.julialang.org/u/ryofurue)
#### Post date: [July 8, 2024, 8:14am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/3 "2024-07-08T08:14:48Z")
> [@abraemer](#):
>
> Are you doing any recursive calls yourself
No. I’ve added a comment about recursion at the end of my initial post for clarity to people who will read my initial post.
> [@abraemer](#):
>
> Reduce your code as much as you can without making the crash disappear
Okay.
---
### Author:  [@mkitti](https://discourse.julialang.org/u/mkitti)
#### Post date: [July 8, 2024, 8:36am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/4 "2024-07-08T08:36:45Z")
What is the Makie call that crashes?
---
### Author:  [@ryofurue](https://discourse.julialang.org/u/ryofurue)
#### Post date: [July 8, 2024, 12:57pm UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/5 "2024-07-08T12:57:57Z")
```julia
c = contourf!(ax, xax, zax, xzarr)
```
After posting my question above, I found that I needed to convert `zax` to a normal array
```julia
. . . , OffsetArrays.no_offset_view(zax), . . .)
```
I knew from experience that `Makie` doesn’t take OffsetArrays, but before this problem hit me, `Makie` used to issue an error message if I make the mistake of sending an OffsetArray.
So, I guess that there is some little bug in the Makie code that tries to convert arrays given as a parameter.
I’m now trying to minimize my code as much as possible. If successful, I’ll submit the example to the Makie repository.
---
### Author:  [@ryofurue](https://discourse.julialang.org/u/ryofurue)
#### Post date: [July 9, 2024, 4:39am UTC](https://discourse.julialang.org/t/crash-illegal-instruction-4-stackoverflowerror-or-freeze/116754/6 "2024-07-09T04:39:37Z")
Here is a small-enough program that reproduces the error:
```julia
using CairoMakie
using OffsetArrays
(im, km_z) = (58, 38)
xax = 0:(im+1)
zax = OffsetArray(Vector{Float64}(undef, km_z+2), 0:km_z+1)
xzsect = zeros(Float64, size(xax,1), size(zax,1))
function plot_xz()
nooffs = OffsetArrays.no_offset_view
fig = Figure()
ax = Axis(fig[1,1])
c = contourf!(ax, xax, zax, nooffs(xzsect)) # -> StackOverflowError
# c = contourf!(ax, xax, nooffs(zax), nooffs(xzsect)) # <- fine
end
plot_xz()
```
In some cases, it produces the above `StackOverflowError` error without any stack trace. In other cases (I don’t see the pattern), it produces this error:
```bash
$ julia try-crash-02.jl
[96975] signal (4.1): Illegal instruction: 4
in expression starting at none:0
_os_unfair_lock_recursive_abort at /usr/lib/system/libsystem_platform.dylib (unknown line)
_os_unfair_lock_lock_slow at /usr/lib/system/libsystem_platform.dylib (unknown line)
Allocations: 7711446 (Pool: 7706794; Big: 4652); GC: 18
fish: Job 1, 'julia try-crash-02.jl' terminated by signal SIGTRAP (Trace or breakpoint trap)
$
```
where “$” is the shell prompt.
I’ve submitted this report to the Makie repository website.