Android demo tutorial running into linking error

[LandonPatmore]

🐛 Describe the bug

I am following the guide here: https://github.com/pytorch/executorch/blob/main/examples/demo-apps/android/ExecuTorchDemo/README.md

cmake . -DCMAKE_INSTALL_PREFIX=cmake-android-out \                                                        
  -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK}/build/cmake/android.toolchain.cmake" \
  -DANDROID_ABI="${ANDROID_ABI}" \
  -DANDROID_PLATFORM=android-24 \
  -DEXECUTORCH_BUILD_XNNPACK=ON \
  -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
  -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
  -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=ON \
  -DEXECUTORCH_BUILD_EXTENSION_TENSOR=ON \
  -Bcmake-android-out

cmake --build cmake-android-out -j16 --target install

cmake extension/android \
  -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK}"/build/cmake/android.toolchain.cmake \
  -DANDROID_ABI="${ANDROID_ABI}" \
  -DCMAKE_INSTALL_PREFIX=cmake-android-out \
  -Bcmake-android-out/extension/android

cmake --build cmake-android-out/extension/android -j16

Everything works until:

cmake --build cmake-android-out/extension/android -j16

[  5%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/ByteBuffer.cpp.o
[ 11%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/Hybrid.cpp.o
[ 17%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/utf8.cpp.o
[ 23%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/Meta.cpp.o
[ 29%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/ReadableByteChannel.cpp.o
[ 35%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/Environment.cpp.o
[ 41%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/lyra/cxa_throw.cpp.o
[ 47%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/lyra/lyra_breakpad.cpp.o
[ 52%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/fbjni.cpp.o
[ 58%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/References.cpp.o
[ 64%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/lyra/lyra.cpp.o
[ 70%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/OnLoad.cpp.o
[ 76%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/lyra/lyra_exceptions.cpp.o
[ 82%] Building CXX object third-party/fbjni/CMakeFiles/fbjni.dir/cxx/fbjni/detail/Exceptions.cpp.o
[ 88%] Linking CXX shared library libfbjni.so
[ 88%] Built target fbjni
[ 94%] Building CXX object CMakeFiles/executorch_jni.dir/jni/jni_layer.cpp.o
[100%] Linking CXX shared library libexecutorch_jni.so
ld: error: undefined symbol: __pread_chk
>>> referenced by unistd.h:128 (/Users/lpatmore/Library/Android/sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include/bits/fortify/unistd.h:128)
>>>               file_data_loader.cpp.o:(executorch::extension::FileDataLoader::load_into(unsigned long, unsigned long, executorch::runtime::DataLoader::SegmentInfo const&, void*) const) in archive /Users/lpatmore/Development/executorch/cmake-android-out/lib/libextension_data_loader.a
>>> did you mean: __read_chk
>>> defined in: /Users/lpatmore/Library/Android/sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/lib/aarch64-linux-android/21/libc.so

ld: error: undefined symbol: stderr
>>> referenced by posix.cpp:101 (/Users/lpatmore/Development/executorch/runtime/platform/default/posix.cpp:101)
>>>               posix.cpp.o:(et_pal_current_ticks) in archive /Users/lpatmore/Development/executorch/cmake-android-out/lib/libexecutorch_core.a
>>> referenced by posix.cpp:101 (/Users/lpatmore/Development/executorch/runtime/platform/default/posix.cpp:101)
>>>               posix.cpp.o:(et_pal_current_ticks) in archive /Users/lpatmore/Development/executorch/cmake-android-out/lib/libexecutorch_core.a
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [libexecutorch_jni.so] Error 1
make[1]: *** [CMakeFiles/executorch_jni.dir/all] Error 2
make: *** [all] Error 2

I have set my exports properly using both NDK 25.1.8937393 and 28.0.12433566 but both cause the same issue. I also tried android-33 instead of android-24, as well as not setting it and it defaulted to android-21, and sadly still the same issue.

Followed this other issue and it seems to have worked for them, but not sure what their NDK version was: #5387

Not sure where to go from here?

Versions

PyTorch version: 2.6.0.dev20240927
Is debug build: False
CUDA used to build PyTorch: None
ROCM used to build PyTorch: N/A

OS: macOS 14.6.1 (arm64)
GCC version: Could not collect
Clang version: 15.0.0 (clang-1500.3.9.4)
CMake version: version 3.30.4
Libc version: N/A

Python version: 3.10.0 (default, Mar 3 2022, 03:54:28) [Clang 12.0.0 ] (64-bit runtime)
Python platform: macOS-14.6.1-arm64-arm-64bit
Is CUDA available: False
CUDA runtime version: No CUDA
CUDA_MODULE_LOADING set to: N/A
GPU models and configuration: No CUDA
Nvidia driver version: No CUDA
cuDNN version: No CUDA
HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True

CPU:
Apple M3 Max

Versions of relevant libraries:
[pip3] executorch==0.5.0a0+70aee72
[pip3] numpy==1.21.3
[pip3] torch==2.6.0.dev20240927
[pip3] torchaudio==2.5.0.dev20240927
[pip3] torchsr==1.0.4
[pip3] torchvision==0.20.0.dev20240927
[conda] executorch 0.5.0a0+70aee72 pypi_0 pypi
[conda] numpy 1.21.3 pypi_0 pypi
[conda] torch 2.6.0.dev20240927 pypi_0 pypi
[conda] torchaudio 2.5.0.dev20240927 pypi_0 pypi
[conda] torchsr 1.0.4 pypi_0 pypi
[conda] torchvision 0.20.0.dev20240927 pypi_0 pypi

[lucylq]

@kirklandsign can you take a look at this?

[kirklandsign]

Hi @LandonPatmore we would recommend NDK r26c for now. Also after you switch NDK version, please rm -rf cmake-android-out*

[kirklandsign]

Please re-open if you still have issue after using r26c and cleaning up your repo.

We have multiple reports about r27 issue. We are working on this.

[kirklandsign]

Hi @LandonPatmore BTW after #6163 we can use NDK 27 as well

[LandonPatmore]

Seems android studio's SDK tools do not break things down into the version your team is referencing. I had to find the r26c version here: https://github.com/android/ndk/releases

Docs should probably be updated to show this since I can see this causing issues for others down the line. But it does work, thanks!

[kirklandsign]

Hi @LandonPatmore r27 should work as well as of now. I will clean up docs

[LandonPatmore]

Looks like this demo app for llama describes what you are referencing: https://github.com/pytorch/executorch/blob/main/examples/demo-apps/android/LlamaDemo/docs/delegates/xnnpack_README.md. Would r27 work here as well or should I stick with r26 for this demo as well? For r27, do I need to be on main or should the v0.30.0 branch suffice? Since that is what the docs state should be cloned. Thanks again!

[kirklandsign]

#6163 is not in v0.3.0. If you want to use r27, please use main.