# Debugging on AU Plugin in Logic on Xcode

**URL:** <https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077>\
**Category:** MacOSX and iOS\
**Created:** [May 14, 2025, 10:45am UTC](https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077 "2025-05-14T10:45:43Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![gpr](https://avatars.discourse-cdn.com/v4/letter/g/2acd7d/32.png) [@gpr](https://forum.juce.com/u/gpr)\
**Post date:** [May 14, 2025, 10:45am UTC](https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077/1 "2025-05-14T10:45:43Z")

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I followed some tutorial ([https://www.youtube.com/watch?v=YwmE82RgTNM&t=318s&ab\_channel=DrBruisin](https://www.youtube.com/watch?v=YwmE82RgTNM&t=318s&ab_channel=DrBruisin)) on how to use Xcode to debug a AU plugin loaded in Logic Pro. The plugin seems to load / execute fine, but I got no breakpoints / assertions / DBG messages. This gives me the impression that there may be something wrong with the symbols or debugging connection.

The setup was very quick and easy:

- Create a “Basic Plugin” project in Projucer, I didn’t really change any code so far
- Export a Xcode project with Debug Settings
- Use the “Edit Scheme” to assign “Logic Pro.app” as the debug Target
- Build and execute

If I run on “My Mac”, Logic starts, and I can load my plugin and it’s shown  
If I try to run on “My Mac (Rosetta)”, Logic starts as well (after a confirmation about Rosetta), but Logic is unable to find my plugin. It’s not show in the list, and if I load a Project with the plugin assigned, I get the Can’t find plugin error.

Anyone has that issues?  
Anyone knows how I could get at least the DBG messages show somewhere?

My System Information:

- Mac Book Pro 2021 / Apple M1 Pro / macOS 15.5 (24F74)
- Logic Pro 11.1.2
- Xcode 16.3
- JUCE Version 8.0.7

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**Author:** ![asimilon](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/asimilon/32/4235_2.png) [@asimilon](https://forum.juce.com/u/asimilon)\
**Post date:** [May 14, 2025, 2:41pm UTC](https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077/2 "2025-05-14T14:41:24Z")

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Bitwig and Logic are a pain to try and debug because of them running plugins in a sandbox process.

iirc with Bitwig you can at least attach to the process manually and get breakpoints at least, I seem to recall this wasn’t possible with Logic, but you definitely won’t get `DBG` statements from either.

I’ve resorted to logging to a file and `tail -f` in Terminal to see the output immediately as a work around. It would be really nice if there was a `#define` flag to re-route `DBG` to a file when needed.

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**Author:** ![kerfuffle](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/kerfuffle/32/11805_2.png) [@kerfuffle](https://forum.juce.com/u/kerfuffle)\
**Post date:** [May 14, 2025, 8:32pm UTC](https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077/3 "2025-05-14T20:32:02Z")

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You can do the following in the constructor of your AudioProcessor:

```c++
std::freopen("/path/to/logfile.txt", "w", stderr);

```

Now `DBG` will write to the file. (Mac only since Windows doesn’t write to stderr.)

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**Author:** ![gpr](https://avatars.discourse-cdn.com/v4/letter/g/2acd7d/32.png) [@gpr](https://forum.juce.com/u/gpr)\
**Post date:** [May 16, 2025, 8:43am UTC](https://forum.juce.com/t/debugging-on-au-plugin-in-logic-on-xcode/66077/4 "2025-05-16T08:43:04Z")

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Thank you. I now also use logging. It’s more cumbersome, but I’ll have no other chance I guess at this point…