No target architecture defined in json file using cmake compile for Android

Ben Hoff

Hey I'm trying to compile an app for android using cmake. When I push the build button, the android_deployment_settings.json file that is produced looks like as follows.

{
    "_description": "This file is generated by QtCreator to be read by androiddeployqt and should not be modified by hand.",
    "application-binary": "libmicrophone-app.so",
    "architectures": {
    },
    "ndk": "/Users/hoff/Library/Android/sdk/ndk/20.1.5948944",
    "ndk-host": "darwin-x86_64",
    "qml-root-path": "/Users/hoff/swdev/microphone-app",
    "qt": "/Users/hoff/Qt/5.12.6/android_x86",
    "sdk": "/Users/hoff/Library/Android/sdk",
    "stdcpp-path": "/Users/hoff/Library/Android/sdk/ndk/20.1.5948944/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/",
    "tool-prefix": "llvm",
    "toolchain-prefix": "llvm",
    "useLLVM": true
}

Then I get an error, No target architecture defined in json file.

Which makes sense, there is no architecture defined. Looking at another project, the json file looks different.

Other non-related project using qmake:

{
   "description": "This file is generated by qmake to be read by androiddeployqt and should not be modified by hand.",
   "qt": "/Users/hoff/Qt/5.12.6/android_x86",
   "sdk": "/Users/hoff/Library/Android/sdk",
   "sdkBuildToolsRevision": "29.0.2",
   "ndk": "/Users/hoff/Library/Android/sdk/ndk/20.1.5948944",
   "toolchain-prefix": "llvm",
   "tool-prefix": "llvm",
   "toolchain-version": "4.9",
   "ndk-host": "darwin-x86_64",
   "target-architecture": "x86",
   "qml-root-path": "/Users/hoff/Qt/Examples/Qt-5.12.6/location/mapviewer",
   "stdcpp-path": "/Users/hoff/Library/Android/sdk/ndk/20.1.5948944/sources/cxx-stl/llvm-libc++/libs/x86/libc++_shared.so",
   "useLLVM": true,
   "application-binary": "/Users/hoff/Qt/Examples/Qt-5.12.6/location/build-mapviewer-Android_for_x86_Clang_Qt_5_12_6_for_Android_x86-Debug/libqml_location_mapviewer.so"
}

You can see the target_architecture is set.

So how do I define the target architecture of x86 for my cmake build?

Ben Hoff

Looks like by this blog that qt just isn't producing the correct android_deployment_settings.json

https://martin.rpdev.net/2018/08/04/building-android-projects-with-qt-creator-and-cmake.html

Might have to do it manually for now.

seijikun

I am currently having the same problem. This worked not too long ago though.
Also interesting:
When QtCreator runs the androiddeployqt executable, the error is a different one: "Cannot find application binary libTestApp.so"

However, when I manually execute everything the way QtCreator does it (at least the way it shows it in [4 Compile Output]), I get the mentioned "No target architecture defined in json file" error.