# How to debug this broadcast warning about iteration?

**URL:** <https://discourse.julialang.org/t/how-to-debug-this-broadcast-warning-about-iteration/15082>\
**Category:** General Usage\
**Created:** [September 17, 2018, 4:31pm UTC](https://discourse.julialang.org/t/how-to-debug-this-broadcast-warning-about-iteration/15082 "2018-09-17T16:31:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![tk3369](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tk3369/32/2824_2.png) [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Post date:** [September 17, 2018, 4:31pm UTC](https://discourse.julialang.org/t/how-to-debug-this-broadcast-warning-about-iteration/15082/1 "2018-09-17T16:31:53Z")

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This warning came up on 0.7 but not 1.0 although my code works fine in 1.0. I have two questions:

1. How do I track down where the problem came from? There isn’t any stack trace.

2. If the behavior hasn’t changed then shouldn’t this warning be retained in 1.0? Or perhaps it has changed but I’m just lucky enough to see it working?

```julia
┌ Warning: broadcast will default to iterating over its arguments in the future. Wrap arguments of
│ type `x::Char` with `Ref(x)` to ensure they broadcast as "scalar" elements.
│ caller = ip:0x0
└ @ Core :-1

```

---

<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [September 17, 2018, 6:39pm UTC](https://discourse.julialang.org/t/how-to-debug-this-broadcast-warning-about-iteration/15082/2 "2018-09-17T18:39:29Z")

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> [@tk3369](#):
>
> - How do I track down where the problem came from? There isn’t any stack trace.

Run with `--depwarn=error`.

> [@tk3369](#):
>
> If the behavior hasn’t changed then shouldn’t this warning be retained in 1.0

The behavior has changed (defaulting to iterating over the arguments).