Fail to compile for Android target armeabi-v7a

[vincent-herlemont]

I have the following error when I try to compile for armeabi-v7a:

[2022-09-23T19:42:47Z INFO  cargo_ndk::cli] Building armeabi-v7a (armv7-linux-androideabi)
   Compiling cfasttext-sys v0.7.0
error: failed to run custom build command for `cfasttext-sys v0.7.0`

Caused by:
  process didn't exit successfully: `/rust/target/debug/build/cfasttext-sys-34b28a9c9dd21f71/build-script-build` (exit status: 101)
  --- stdout
  CMAKE_TOOLCHAIN_FILE_armv7-linux-androideabi = None
  CMAKE_TOOLCHAIN_FILE_armv7_linux_androideabi = None
  TARGET_CMAKE_TOOLCHAIN_FILE = None
  CMAKE_TOOLCHAIN_FILE = None
  CMAKE_GENERATOR_armv7-linux-androideabi = None
  CMAKE_GENERATOR_armv7_linux_androideabi = None
  TARGET_CMAKE_GENERATOR = None
  CMAKE_GENERATOR = None
  CMAKE_PREFIX_PATH_armv7-linux-androideabi = None
  CMAKE_PREFIX_PATH_armv7_linux_androideabi = None
  TARGET_CMAKE_PREFIX_PATH = None
  CMAKE_PREFIX_PATH = None
  CMAKE_armv7-linux-androideabi = None
  CMAKE_armv7_linux_androideabi = None
  TARGET_CMAKE = None
  CMAKE = None
  running: "cmake" "/.cargo/registry/src/github.aaakk.us.kg-1ecc6299db9ec823/cfasttext-sys-0.7.0/cfasttext" "-DCMAKE_INSTALL_PREFIX=/IdeaProjects/rust/target/armv7-linux-androideabi/debug/build/cfasttext-sys-97389a1d85d6c5c7/out" "-DCMAKE_C_FLAGS= -DANDROID -ffunction-sections -fdata-sections -fPIC" "-DCMAKE_C_COMPILER=/Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang" "-DCMAKE_CXX_FLAGS= -DANDROID -ffunction-sections -fdata-sections -fPIC" "-DCMAKE_CXX_COMPILER=/Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang++" "-DCMAKE_ASM_FLAGS= -DANDROID -ffunction-sections -fdata-sections -fPIC" "-DCMAKE_ASM_COMPILER=/Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang" "-DCMAKE_BUILD_TYPE=Debug"
  -- The C compiler identification is Clang 11.0.5
  -- The CXX compiler identification is Clang 11.0.5
  -- Check for working C compiler: /Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang
  -- Check for working C compiler: /Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang -- works
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - done
  -- Detecting C compile features
  -- Detecting C compile features - done
  -- Check for working CXX compiler: /Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang++
  -- Check for working CXX compiler: /Android/Sdk/ndk/22.1.7171670/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang++ -- works
  -- Detecting CXX compiler ABI info
  -- Detecting CXX compiler ABI info - done
  -- Detecting CXX compile features
  -- Detecting CXX compile features - done
  -- Configuring done
  -- Generating done
  -- Build files have been written to: /IdeaProjects/rust/target/armv7-linux-androideabi/debug/build/cfasttext-sys-97389a1d85d6c5c7/out/build
  running: "cmake" "--build" "." "--target" "cfasttext_static" "--config" "Debug" "--parallel" "8"
  Scanning dependencies of target objlib
  Scanning dependencies of target fasttext-static
  [ 35%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/args.cc.o
  [ 35%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/main.cc.o
  [  5%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/autotune.cc.o
  [ 35%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/dictionary.cc.o
  [ 35%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/densematrix.cc.o
  [ 41%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/fasttext.cc.o
  [ 41%] Building CXX object fasttext/CMakeFiles/fasttext-static.dir/src/loss.cc.o
  [ 47%] Building CXX object CMakeFiles/objlib.dir/lib/cfasttext.cc.o
  [ 47%] Built target objlib

  --- stderr
  CMake Warning:
    Manually-specified variables were not used by the project:

      CMAKE_ASM_COMPILER
      CMAKE_ASM_FLAGS


  make: warning: -j8 forced in submake: resetting jobserver mode.
  clang++clang++clang++clang++clang++clang++: clang++error: : : : : : errorerrorerrorerror: : the clang compiler does not support '-march=native'the clang compiler does not support '-march=native': : 
  the clang compiler does not support '-march=native'
  the clang compiler does not support '-march=native'
  the clang compiler does not support '-march=native'

  error: the clang compiler does not support '-march=native'
  : error: the clang compiler does not support '-march=native'
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:141: fasttext/CMakeFiles/fasttext-static.dir/src/main.cc.o] Error 1
  make[3]: *** Waiting for unfinished jobs....
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:63: fasttext/CMakeFiles/fasttext-static.dir/src/args.cc.o] Error 1
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:76: fasttext/CMakeFiles/fasttext-static.dir/src/autotune.cc.o] Error 1
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:115: fasttext/CMakeFiles/fasttext-static.dir/src/fasttext.cc.o] Error 1
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:128: fasttext/CMakeFiles/fasttext-static.dir/src/loss.cc.o] Error 1
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:89: fasttext/CMakeFiles/fasttext-static.dir/src/densematrix.cc.o] Error 1
  make[3]: *** [fasttext/CMakeFiles/fasttext-static.dir/build.make:102: fasttext/CMakeFiles/fasttext-static.dir/src/dictionary.cc.o] Error 1
  make[2]: *** [CMakeFiles/Makefile2:242: fasttext/CMakeFiles/fasttext-static.dir/all] Error 2
  make[2]: *** Waiting for unfinished jobs....
  make[1]: *** [CMakeFiles/Makefile2:113: CMakeFiles/cfasttext_static.dir/rule] Error 2
  make: *** [Makefile:164: cfasttext_static] Error 2
  thread 'main' panicked at '
  command did not execute successfully, got: exit status: 2

  build script failed, must exit now', /.cargo/registry/src/github.aaakk.us.kg-1ecc6299db9ec823/cmake-0.1.48/src/lib.rs:975:5
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[2022-09-23T19:42:50Z INFO  cargo_ndk::cli] If the build failed due to a missing target, you can run this command:
[2022-09-23T19:42:50Z INFO  cargo_ndk::cli] 
[2022-09-23T19:42:50Z INFO  cargo_ndk::cli]     rustup target install armv7-linux-androideabi

[messense]

cmake-rs does not have good cross compiling support, see rust-lang/cmake-rs#80.

You'll need to use a cmake toolchain file at the moment.