Android build failing, undefined symbol: internal_storage_path & asset_manager

[Alireza-Ta]

Hi There! I'm trying to build one of official examples for Android but I'm getting following errors for both arm and arm64 architectures.

package main

import (
    rl "github.com/gen2brain/raylib-go/raylib"
)

func init() {
    rl.SetCallbackFunc(main)
}
func main() {
    screenWidth := int32(800)
    screenHeight := int32(450)

    rl.SetConfigFlags(rl.FlagVsyncHint)

    rl.InitWindow(screenWidth, screenHeight, "Android example")

    rl.SetConfigFlags(rl.FlagVsyncHint)

    for !rl.WindowShouldClose() {
        rl.BeginDrawing()

        rl.ClearBackground(rl.RayWhite)

        rl.DrawText("Congrats! You created your first window!", 190, 200, 20, rl.LightGray)

        rl.EndDrawing()
    }

    rl.CloseWindow()
}

ld: error: undefined symbol: internal_storage_path
>>> referenced by platform_android.c
>>>               ..\..\..\..\AppData\Local\Temp\go-link-3058170194\000014.o:(android_init)

ld: error: undefined symbol: asset_manager
>>> referenced by platform_android.c
>>>               ..\..\..\..\AppData\Local\Temp\go-link-3058170194\000014.o:(android_init)
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Thanks!

[gen2brain]

And this is the output of what command?

[Alireza-Ta]

Following Android build instructions in Android README example. When building for arm and executing ./gradlew assembleDebug command, it gives me following error in actual Android device:

java.lang.UnsatisfiedLinkError: Unable to load native library
"/data/app/~~3eAjrD7WdwqbBWolWZ6G8w==/com.example.android-
EHfqIoxxoNrUe8SXrq_smA==/base.apk!/lib/armeabi-v7a/libexample.so": dlopen failed: cannot locate symbol 
"internal_storage_path" referenced by "/data/app/~~3eAjrD7WdwqbBWolWZ6G8w==/com.example.android-
EHfqIoxxoNrUe8SXrq_smA==/base.apk!/lib/armeabi-v7a/libexample.so"...
 at android.app.NativeActivity.onCreate(NativeActivity.java:178)
 at android.app.Activity.performCreate(Activity.java:8508)
 at android.app.Activity.performCreate(Activity.java:8472)
 at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1417)
 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3786)
 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3951)
 at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101)
 at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
 at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2405)
 at android.os.Handler.dispatchMessage(Handler.java:106)
 at android.os.Looper.loopOnce(Looper.java:211)
 at android.os.Looper.loop(Looper.java:300)
 at android.app.ActivityThread.main(ActivityThread.java:8152)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1028)

As you see in the error it states dlopen failed: cannot locate symbol "internal_storage_path". To find where actually this undefined symbol happens, added -z,defs flag to compile shared library command(this flag basically throws error when it hits to an undefined symbol) like so -ldflags="-s -w -extldflags=-Wl,-z,defs,-soname,libexample.so" and it gave me the linker error in the initial post.

CC="F:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/bin/armv7a-linux-androideabi31-clang" \
CGO_CFLAGS="-IF:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/sysroot/usr/include -IF:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/sysroot/usr/include/arm-linux-androideabi --sysroot=F:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/sysroot" \
CGO_LDFLAGS="-LF:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/sysroot/usr/lib/arm-linux-androideabi/31 -LF:/Android-SDK/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/lib" \
GOOS=android GOARCH=arm CGO_ENABLED=1 go build -buildmode=c-shared -ldflags="-s -w -extldflags=-Wl,-soname,libexample.so" \
-o=android/libs/armeabi-v7a/libexample.so

ld: error: undefined symbol: internal_storage_path
>>> referenced by platform_android.c
>>>               ..\..\..\..\AppData\Local\Temp\go-link-3058170194\000014.o:(android_init)

ld: error: undefined symbol: asset_manager
>>> referenced by platform_android.c
>>>               ..\..\..\..\AppData\Local\Temp\go-link-3058170194\000014.o:(android_init)
clang: error: linker command failed with exit code 1 (use -v to see invocation)

[gen2brain]

Thanks, now it is clear what and where the error is, with the first post nobody could guess. Can you try to build a shared library without stripping symbols, i.e., remove -s -w from ldflags?

[Alireza-Ta]

Still gives the same error.

[gen2brain]

This should be fixed in https://github.com/gen2brain/raylib-go/commit/069b39e6886e869cb2b1f1a8a4a7c61ceba5176f, and the example is updated.

[Alireza-Ta]

Thank you for the quick fix!