[bug] Android cross compilation not working. Targets not getting linked

[feliwir]

Environment details

• Operating System+version: Fedora 40 / Android 24
• Compiler+version: clang 17
• Conan version: 2.0.14
• Python version: Python 3.12.0

Steps to reproduce

I was mostly following https://docs.conan.io/2/examples/cross_build/android/android_studio.html#examples-cross-build-android-studio except for some fixes i had to do for Conan2:

• Use build=missing
• Use --output-folder to put the files in the right place
• Only build release packages

My Android profile

include(default)

[settings]
os=Android
os.api_level=24
compiler=clang
compiler.version=17
compiler.libcxx=c++_static
compiler.cppstd=17

[conf]
tools.android:ndk_path=/home/stephan/Android/Sdk/ndk/25.1.8937393

My build.gradle (relevant portions)

task conanInstall {
    def conanExecutable = "conan" // define the path to your conan installation
    def buildDir = new File("app/build")
    buildDir.mkdirs()
    // Don't build the debug configurations
    ["Release"].each { String build_type ->
        ["armv7", "armv8", "x86", "x86_64"].each { String arch ->
            def cmd = conanExecutable + " install " +
                    "../../../../../../ --profile android -s build_type="+ build_type +" -s arch=" + arch +
                    " --build=missing --output-folder=conan-"+ arch +" -c tools.cmake.cmake_layout:build_folder_vars=['settings.arch']"
            print(">> ${cmd} \n")

            def sout = new StringBuilder(), serr = new StringBuilder()
            def proc = cmd.execute(null, buildDir)
            proc.consumeProcessOutput(sout, serr)
            proc.waitFor()
            println "$sout $serr"
            if (proc.exitValue() != 0) {
                throw new Exception("out> $sout err> $serr" + "\nCommand: ${cmd}")
            }
        }
    }
}

android {
    compileSdkVersion 33
    ndkVersion '25.1.8937393'

    buildFeatures {
        prefab true
    }

    defaultConfig {
        minSdkVersion 24
        targetSdkVersion 33
        versionCode 258
        versionName "6.8.7"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                arguments "-DMES_MOBILE_BUILD=TRUE", "-DANDROID_STL=c++_shared", "-DCMAKE_TOOLCHAIN_FILE=./Applications/pocket/client/droid/app/conan_android_toolchain.cmake"
                cppFlags "-DMES_MOBILE_BUILD", "-fsigned-char","-fPIC",
                        "-D_LIBCPP_HAS_NO_OFF_T_FUNCTIONS"
            }
        }
    }

    externalNativeBuild {
        cmake {
            path file('../../../../../CMakeLists.txt')
            version "3.22.1"
        }
    }
    namespace 'org.mes'
}

My toolchain:

 # During multiple stages of CMake configuration, the toolchain file is processed and command-line
 # variables may not be always available. The script exits prematurely if essential variables are absent.

 if ( NOT ANDROID_ABI )
     message(FATAL_ERROR "Please specify ANDROID_ABI")
     return()
 endif()
 if(${ANDROID_ABI} STREQUAL "x86_64")
     message(STATUS "Using x86_64 toolchain")
     include("${CMAKE_CURRENT_LIST_DIR}/build/conan-x86_64/conan_toolchain.cmake")
 elseif(${ANDROID_ABI} STREQUAL "x86")
     message(STATUS "Using x86 toolchain")
     include("${CMAKE_CURRENT_LIST_DIR}/build/conan-x86/conan_toolchain.cmake")
 elseif(${ANDROID_ABI} STREQUAL "arm64-v8a")
     message(STATUS "Using arm64-v8a toolchain")
     include("${CMAKE_CURRENT_LIST_DIR}/build/conan-armv8/conan_toolchain.cmake")
 elseif(${ANDROID_ABI} STREQUAL "armeabi-v7a")
     message(STATUS "Using armeabi-v7a toolchain")
     include("${CMAKE_CURRENT_LIST_DIR}/build/conan-armv7/conan_toolchain.cmake")
 else()
     message(FATAL "Not supported configuration")
 endif()

Logs

No response

[elvisdukaj]

I created a Conan plugin for gradle that is exactly doing that. If you're still interested, I can share the code with you.