buildozer + Cython + C++ 库：dlopen 失败：找不到 module.so 引用的符号符号名称

Question

phase_engine.so 尝试使用_ZTINSt6__ndk18ios_base7failureE 却找不到：

11-08 19:59:00.629 25777 25823 I python  :  Traceback (most recent call last):
11-08 19:59:00.629 25777 25823 I python  :    File "/home/sonoflilit/phase/phase/.buildozer/android/app/main.py", line 14, in <module>
11-08 19:59:00.629 25777 25823 I python  :  ImportError: dlopen failed: cannot locate symbol "_ZTINSt6__ndk18ios_base7failureE" referenced by "/data/data/il.co.loris.phase/files/app/_python_bundle/site-packages/phase_engine.so"...
11-08 19:59:00.630 25777 25823 I python  : Python for android ended.

存在于libc++_shared.so:

apk$ readelf -s --wide lib/armeabi-v7a/libc++_shared.so | grep _ZTINSt6__ndk18ios_base7failureE
   690: 000885c0    12 OBJECT  GLOBAL DEFAULT   17 _ZTINSt6__ndk18ios_base7failureE

不是phase_engine.so动态链接的

apk/assets$ readelf -a _python_bundle/site-packages/phase_engine.so | grep lib
 0x00000001 (NEEDED)                     Shared library: [libpython3.8m.so]
 0x00000001 (NEEDED)                     Shared library: [libdl.so]
 0x00000001 (NEEDED)                     Shared library: [libc.so]
  000000: Rev: 1  Flags: BASE  Index: 1  Cnt: 1  Name: build/lib.linux-x86_64-3.8/phase_engine.cpython-38-x86_64-linux-gnu.so
  000000: Version: 1  File: libc.so  Cnt: 1
  0x0020: Version: 1  File: libdl.so  Cnt: 1

尽管我在setup.py 中很好地询问了libraries = ['c++'],（肯定会运行）：

from setuptools import setup, Extension
from Cython.Build import cythonize

setup(
    name = 'phase-engine',
    version = '0.1',
    ext_modules = cythonize([Extension("phase_engine",
        ["phase_engine.pyx"] + ['music-synthesizer-for-android/src/' + p for p in [
            ..., 'synth_unit.cc'
        ]],
        include_path = ['music-synthesizer-for-android/src/'],
        language = 'c++',
        libraries = ['c++'],
    )])
)

我做错了什么？

Answer 1

首先，c++ 当然应该是c++_shared，因为库被称为libc++_shared.so。

其次，我无法让它与 setup.py 一起使用，但是通过配方向环境添加编译器标志很容易，numpy 配方就是这样做的：

class MyRecipe(IncludedFilesBehaviour, CppCompiledComponentsPythonRecipe):
    version = 'stable'
    src_filename = "../../../phase-engine"
    name = 'phase-engine'

    depends = ['setuptools']

    call_hostpython_via_targetpython = False
    install_in_hostpython = True

    def get_recipe_env(self, arch):
        env = super().get_recipe_env(arch)
        env['LDFLAGS'] += ' -lc++_shared'
        return env

recipe = MyRecipe()