Issue with Audio Unit on 10.11

Hi Guys,

I used to use 10.12 SDK with a 10.9 deployment target but since enabling ARM architecture, I cannot do that anymore, and just use the 10.9 deployment target but with the 11.0 SDK

I have issue an issue on older OSX versions with AudioUnit not loading with the following issue
Symbol not found: __os_crash_fmt

Does this ring a bell to someone ?

Thanks !

This doesn’t ring a bell. I tried to repro, although I don’t have a 10.9 machine for testing. Instead, I tried building with a 10.9 deployment target and then inspecting the final build output with nm to see whether the os_crash_fmt symbol was listed as undefined. With Xcode 12.4 (macOS 11.1 SDK), neither the Debug nor Release mode builds of the DSPModulePluginDemo seem to require this symbol at all.

Perhaps you could try running nm on all of your plugin object files and dependencies and check whether any of these are depending on this symbol. At least then you’ll know where the symbol is being used, and you may then be able to take steps to avoid using the symbol altogether (adjusting deployment targets of dependencies, removing dependencies etc).

Weirdly I don’t find the symbol in the binary, but here is the full info from the crashlog

dlopen(/Library/Audio/Plug-Ins/Components/UVIWorkstationAU.component/Contents/MacOS/UVIWorkstationAU, 262): Symbol not found: __os_crash_fmt
  Referenced from: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
  Expected in: /usr/lib/libSystem.B.dylib
 in /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice)

That’s very odd. It looks to me like the missing symbol is required by a platform library, so I’m not sure how one could work around the problem.

yep… I have asked Apple about this. I will let you guys know if I get some feedback on this.
The issue was that I can’t have a per arch SDK even though Xcode allows it, it doesn’t work :slight_smile:

One of my users (running 10.11) reported this exact same issue today. I haven’t looked into it closely, but I’m interested in what you discover.

FYI, I’m building with Xcode 12.4 which uses 11.1 SDK and setting a deployment target of 10.11.