[Bug]: VST3 scanner crashes with SIGSEGV on Spectrasonics plugins (Keyscape, Trilian)

[irvall]

Detailed steps on how to reproduce the bug

1. Install Spectrasonics Keyscape 1.5.2c (or Trilian)

• Available at: /Library/Audio/Plug-Ins/VST3/Keyscape.vst3 (macOS)

2. Build JUCE AudioPluginHost or any JUCE-based VST3 scanner

• Using JUCE 8.0.10
• macOS arm64 (but likely affects all platforms)

3. Attempt to scan the Keyscape plugin

• Either through AudioPluginHost's plugin menu or programmatically via VST3PluginFormat::createPluginInstance()

4. Observe crash with SIGSEGV

• Crash occurs at this line during parameter initialization:
  

  JUCE/modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp

  Line 105 in 1b460fe

  auto count = controller.getParameterCount();

What is the expected behaviour?

Plugin should load successfully (with or without parameters), similar to how Logic Pro, Ableton Live, and other DAWs handle it. Debug dump from successful Omnisphere scanning:

Debug mode - plugin data: {
  "Name": "Omnisphere",
  "Vendor": "Spectrasonics",
  "Version": "3.0.0",
  "Category": "Instrument|Synth",
  "Type": "Instrument",
  "Format": "VST3",
  "Identifier": "/Library/Audio/Plug-Ins/VST3/Omnisphere.vst3",
  "Parameters": [
    {
      "Name": "Param 0",
      "Index": 0,
      "UniqueId": "0",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 1",
      "Index": 1,
      "UniqueId": "1",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 2",
      "Index": 2,
      "UniqueId": "2",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 3",
      "Index": 3,
      "UniqueId": "3",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 4",
      "Index": 4,
      "UniqueId": "4",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 5",
      "Index": 5,
      "UniqueId": "5",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
    {
      "Name": "Param 6",
      "Index": 6,
      "UniqueId": "6",
      "Steps": 2147483647,
      "Discrete": false,
      "MetaParamter": false,
      "Automatable": true,
      "Orientation": "Normal",
      "Unit": "",
      "DefaultValue": 0.0,
      "ValueStrings": [],
      "Bypass": false,
      "Category": 0,
      "Boolean": false
    },
...

Operating systems

macOS

What versions of the operating systems?

15.7.2 (24G325)

Architectures

Arm64/aarch64

Stacktrace

* thread #1, name = 'JUCE v8.0.10: Message Thread', queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x180)
    frame #0: 0x000000010c209eb4 Keyscape`___lldb_unnamed_symbol5130 + 12
  * frame #1: 0x0000000102a17c48 PluginScanner`juce::getAllParamIDs(controller=0x0000000109ee5770) at juce_VST3PluginFormat.cpp:105:29
    frame #2: 0x0000000102a17538 PluginScanner`juce::VST3PluginInstance::initialiseParameterList(this=0x000000010b02d000) at juce_VST3PluginFormat.cpp:3568:27
    frame #3: 0x0000000102a16950 PluginScanner`juce::VST3PluginInstance::initialise()::'lambda'()::operator()(this=0x000000016d6898d8) const at juce_VST3PluginFormat.cpp:2675:13
    frame #4: 0x00000001029f1d18 PluginScanner`juce::VST3PluginInstance::initialise(this=0x000000010b02d000) at juce_VST3PluginFormat.cpp:2680:9
    frame #5: 0x000000010296bfb8 PluginScanner`juce::createVST3Instance(format=0x0000600003fab380, description=0x0000600001bb0180, file=0x000000016d689a10) at juce_VST3PluginFormat.cpp:4203:21
    frame #6: 0x000000010296bc0c PluginScanner`juce::VST3PluginFormat::createPluginInstance(this=0x0000600003fab380, description=0x0000600001bb0180, (null)=44100, (null)=512, callback=juce::AudioPluginFormat::PluginCreationCallback @ 0x000000016d689bc8) at juce_VST3PluginFormat.cpp:4228:27
    frame #7: 0x0000000102922b4c PluginScanner`juce::AudioPluginFormat::createInstanceFromDescription(this=0x0000600003fab380, desc=0x0000600001bb0180, initialSampleRate=44100, initialBufferSize=512, errorMessage=0x000000016d68a318) at juce_AudioPluginFormat.cpp:74:9
    frame #8: 0x000000010277a910 PluginScanner`PluginScannerApplication::parseDescription(this=0x000000012f031e00, desc=0x0000600001bb0180) at Main.cpp:473:44
    frame #9: 0x0000000102778fb8 PluginScanner`PluginScannerApplication::loadPlugin(this=0x000000012f031e00, pluginPathOrIdentifier=String @ 0x000000016d68a748, client=0x000000016d68a8d8) at Main.cpp:341:39
    frame #10: 0x0000000102776274 PluginScanner`PluginScannerApplication::initialise(this=0x000000012f031e00, commandLine=0x000000016d68a9b0) at Main.cpp:188:4
    frame #11: 0x0000000102be6f34 PluginScanner`juce::JUCEApplicationBase::initialiseApp(this=0x000000012f031e00) at juce_ApplicationBase.cpp:312:5
    frame #12: 0x0000000102ffb9a8 PluginScanner`juce::JUCEApplication::initialiseApp(this=0x000000012f031e00) at juce_Application.cpp:97:30
    frame #13: 0x0000000102be6cb8 PluginScanner`juce::JUCEApplicationBase::main() at juce_ApplicationBase.cpp:271:16
    frame #14: 0x0000000102be6b3c PluginScanner`juce::JUCEApplicationBase::main(argc=5, argv=0x000000016d68b128) at juce_ApplicationBase.cpp:255:16
    frame #15: 0x00000001027757a0 PluginScanner`main(argc=5, argv=0x000000016d68b128) at Main.cpp:820:1
    frame #16: 0x00000001834f2b98 dyld`start + 6076

Plug-in formats (if applicable)

VST3

Plug-in host applications (DAWs) (if applicable)

No response

Testing on the develop branch

The bug is present on the develop branch

Code of Conduct

• I agree to follow the Code of Conduct

Misc.

Looks related: spotify/pedalboard#346

[Anthony-Nicholls]

Hi @irvall thanks for reporting, could you please confirm that you are seeing this behaviour on the latest version of JUCE. I don't think we would have intentionally changed the behaviour but a lot of the audio processor has been recently moved around and I have at least one report of someone managing to load these plugins using 8.0.11.

[irvall]

Hi @Anthony-Nicholls! Thanks for getting back on this. I've just fetched all the upstream changes and rebuilt everything. Unfortunately, I'm still experiencing issues with VST3 scanning:

• Scanning completes successfully for Omnisphere.vst3

• Scanning crashes for Keyscape.vst3

The crash occurs at same location - line 112 in juce_VST3PluginFormatImpl.h:

JUCE/modules/juce_audio_processors_headless/format_types/juce_VST3PluginFormatImpl.h

Line 112 in c352e24

auto count = controller.getParameterCount();

Both plugins are from the same vendor (Spectrasonics). Is there something specific about Keyscape that might be triggering this issue? Happy to provide more debug information if that would help.

[aceaudio]

@irvall thanks for checking. I've reached out to the manufacturer to see if we can resolve this issue.