# Lots of errors in Juce library code when building with JUCE\_USE\_CUSTOM\_PLUGIN\_STANDALONE\_APP=1 **URL:** \ **Category:** General JUCE discussion\ **Created:** [April 16, 2021, 8:46am UTC](https://forum.juce.com/t/lots-of-errors-in-juce-library-code-when-building-with-juce-use-custom-plugin-standalone-app-1/45535 "2021-04-16T08:46:46Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![benvining](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/benvining/32/9922_2.png) [@benvining](https://forum.juce.com/u/benvining)\ **Post date:** [April 16, 2021, 8:46am UTC](https://forum.juce.com/t/lots-of-errors-in-juce-library-code-when-building-with-juce-use-custom-plugin-standalone-app-1/45535/1 "2021-04-16T08:46:46Z")
Hello, I’ve been experimenting with implementing my own version of the StandaloneFilterApp class. In my project’s CMakeLists.txt, I set JUCE\_USE\_CUSTOM\_PLUGIN\_STANDALONE\_APP=1 and added my new sources to the shared target, and in my header file I have this: ```cpp #include #include extern juce::JUCEApplicationBase* juce_CreateApplication(); class StandaloneFilterApp : public juce::JUCEApplication { public: StandaloneFilterApp(); const juce::String getApplicationName() override { return JucePlugin_Name; } const juce::String getApplicationVersion() override { return JucePlugin_VersionString; } bool moreThanOneInstanceAllowed() override { return true; } void anotherInstanceStarted(const juce::String&) override {} virtual juce::StandaloneFilterWindow* createWindow(); void initialise(const juce::String&) override; void shutdown() override; void systemRequestedQuit() override; private: juce::ApplicationProperties appProperties; std::unique_ptr mainWindow; void requestQuit() const; }; ``` when I run the build, it fails and gives me a lot of errors in the Juce library code, what appear to be undefined types: ```auto In file included from /home/runner/work/imogen/imogen/imogen/Source/StandaloneWrapper/StandaloneWrapper.h:6, from /home/runner/work/imogen/imogen/imogen/Source/StandaloneWrapper/StandaloneWrapper.cpp:1: /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:558:21: error: ‘deviceManager’ was not declared in this scope 558 | deviceManager.setMidiInputDeviceEnabled (oldDevice.identifier, false); | ^ ~~~~~~~~~~~~ /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:561:39: error: request for member ‘contains’ in ‘((juce::StandalonePluginHolder*)this)->juce::StandalonePluginHolder::lastMidiDevices’, which is of non-class type ‘int’ 561 | if (! lastMidiDevices.contains (newDevice)) | ^ ~~~~~~~ /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:562:21: error: ‘deviceManager’ was not declared in this scope 562 | deviceManager.setMidiInputDeviceEnabled (newDevice.identifier, true); | ^ ~~~~~~~~~~~~ /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h: At global scope: /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:599:35: error: ‘AudioDeviceManager’ does not name a type 599 | const AudioDeviceManager::AudioDeviceSetup* preferredSetupOptions = nullptr, | ^ ~~~~~~~~~~~~~~~~~ /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:599:71: error: expected unqualified-id before ‘*’ token 599 | const AudioDeviceManager::AudioDeviceSetup* preferredSetupOptions = nullptr, | ^ /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:599:71: error: expected ‘)’ before ‘*’ token 599 | const AudioDeviceManager::AudioDeviceSetup* preferredSetupOptions = nullptr, | ^ | ) /home/runner/work/imogen/imogen/imogen/Builds/_deps/juce-src/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h:594:28: note: to match this ‘(’ 594 | StandaloneFilterWindow (const String& title, | ^ ``` Did I do something wrong in setting this up, or is this an error in juce\_StandaloneFilterWindow.h? ---
**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\ **Post date:** [April 16, 2021, 9:16am UTC](https://forum.juce.com/t/lots-of-errors-in-juce-library-code-when-building-with-juce-use-custom-plugin-standalone-app-1/45535/2 "2021-04-16T09:16:57Z")
The standalone header requires that `juce_audio_utils` has been previously included. Adding the extra include after the `juce_audio_plugin_client` include should fix the issue. ---
**Author:** ![benvining](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/benvining/32/9922_2.png) [@benvining](https://forum.juce.com/u/benvining)\ **Post date:** [April 16, 2021, 5:16pm UTC](https://forum.juce.com/t/lots-of-errors-in-juce-library-code-when-building-with-juce-use-custom-plugin-standalone-app-1/45535/3 "2021-04-16T17:16:17Z")
Thank you for the info! I’m not at my computer now, but I will try this later today. Might I suggest updating the audio\_plugin\_client module’s documentation? Last night I thought the problem might be a missing juce header, so I looked at the audio\_plugin\_client module declaration block in its header, and it lists a single dependancy of juce\_audio\_processors. But when I included that module header in my custom standalone filter header, I got these same errors. ---
**Author:** ![benvining](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/benvining/32/9922_2.png) [@benvining](https://forum.juce.com/u/benvining)\ **Post date:** [April 16, 2021, 6:33pm UTC](https://forum.juce.com/t/lots-of-errors-in-juce-library-code-when-building-with-juce-use-custom-plugin-standalone-app-1/45535/4 "2021-04-16T18:33:56Z")
The build is successful with that `#include` addition. Thank you!!