Issues when installing python wrapper on Windows

[myfatemi04]

I'm trying to install Apriltag with Python, and it keeps giving me an error during the build stage.

I'm on Windows 10, and the python wrapper for OpenCV 2 works for me.

Does anyone know how I could fix this?

Other people have had this problem too.

Here's the whole error log:

    Installing collected packages: apriltag
    Running setup.py install for apriltag ... error
    ERROR: Command errored out with exit status 1:
     command: 'C:\Users\legoc\Desktop\Augmented Reality\env\Scripts\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\legoc\\AppData\\Local\\Temp\\pip-install-0vcggsia\\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\\setup.py'"'"'; __file__='"'"'C:\\Users\\legoc\\AppData\\Local\\Temp\\pip-install-0vcggsia\\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\legoc\AppData\Local\Temp\pip-record-cyusenbz\install-record.txt' --single-version-externally-managed --compile --install-headers 'C:\Users\legoc\Desktop\Augmented Reality\env\include\site\python3.8\apriltag'
         cwd: C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\
    Complete output (78 lines):
    running install
    running build
    running build_py
    creating build
    creating build\lib.win-amd64-3.8
    copying python\apriltag.py -> build\lib.win-amd64-3.8
    running build_ext
    -- Building for: Visual Studio 16 2019
    -- Selecting Windows SDK version 10.0.18362.0 to target Windows 10.0.19041.
    -- The C compiler identification is MSVC 19.27.29112.0
    -- The CXX compiler identification is MSVC 19.27.29112.0
    -- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe
    -- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe - 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: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe
    -- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe - works
    -- Detecting CXX compiler ABI info
    -- Detecting CXX compiler ABI info - done
    -- Detecting CXX compile features
    -- Detecting CXX compile features - done
    -- Looking for pthread.h
    -- Looking for pthread.h - not found
    -- Found Threads: TRUE
    -- Could NOT find PkgConfig (missing: PKG_CONFIG_EXECUTABLE)
    -- Checking for one of the modules 'opencv>=2.3;opencv-2.3.1;opencv-3.0.0'
    -- Configuring done
    -- Generating done
    CMake Warning:
      Manually-specified variables were not used by the project:

        PYTHON_EXECUTABLE


    -- Build files have been written to: C:/Users/legoc/AppData/Local/Temp/pip-install-0vcggsia/apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa/build/temp.win-amd64-3.8/Release
    Microsoft (R) Build Engine version 16.7.0+b89cb5fde for .NET Framework
    Copyright (C) Microsoft Corporation. All rights reserved.

    C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets(499,5): warning MSB8029: The Intermediate directory or Output directory cannot reside under the Temporary directory as it could lead to issues with incremental build. [C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\build\temp.win-amd64-3.8\Release\ZERO_CHECK.vcxproj]
      Checking Build System
    C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets(499,5): warning MSB8029: The Intermediate directory or Output directory cannot reside under the Temporary directory as it could lead to issues with incremental build. [C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\build\temp.win-amd64-3.8\Release\core\apriltag.vcxproj]
      Building Custom Rule C:/Users/legoc/AppData/Local/Temp/pip-install-0vcggsia/apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa/core/CMakeLists.txt  
    cl : command line error D8021: invalid numeric argument '/Wsign-compare' [C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\build\temp.win-amd64-3.8\Release\core\apriltag.vcxproj]
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\setup.py", line 62, in <module>     
        setup(
      File "C:\Users\legoc\Desktop\Augmented Reality\env\lib\site-packages\setuptools\__init__.py", line 145, in setup
        return distutils.core.setup(**attrs)
      File "C:\Program Files\Python38\lib\distutils\core.py", line 148, in setup
        dist.run_commands()
      File "C:\Program Files\Python38\lib\distutils\dist.py", line 966, in run_commands
        self.run_command(cmd)
      File "C:\Program Files\Python38\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "C:\Users\legoc\Desktop\Augmented Reality\env\lib\site-packages\setuptools\command\install.py", line 61, in run
        return orig.install.run(self)
      File "C:\Program Files\Python38\lib\distutils\command\install.py", line 545, in run
        self.run_command('build')
      File "C:\Program Files\Python38\lib\distutils\cmd.py", line 313, in run_command
        self.distribution.run_command(command)
      File "C:\Program Files\Python38\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "C:\Program Files\Python38\lib\distutils\command\build.py", line 135, in run
        self.run_command(cmd_name)
      File "C:\Program Files\Python38\lib\distutils\cmd.py", line 313, in run_command
        self.distribution.run_command(command)
      File "C:\Program Files\Python38\lib\distutils\dist.py", line 985, in run_command
        cmd_obj.run()
      File "C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\setup.py", line 35, in run
        self.build_extension(ext)
      File "C:\Users\legoc\AppData\Local\Temp\pip-install-0vcggsia\apriltag_da105f092a3b4ae28f7e4c4a3c0e00fa\setup.py", line 60, in build_extension
        subprocess.check_call(['cmake', '--build', '.'] + build_args, cwd=self.build_temp)
      File "C:\Program Files\Python38\lib\subprocess.py", line 364, in check_call
        raise CalledProcessError(retcode, cmd)
    subprocess.CalledProcessError: Command '['cmake', '--build', '.', '--config', 'Release', '--', '/m']' returned non-zero exit status 1.       
    ----------------------------------------```

[trzy]

It won't build on Windows, not directly at least. I got it to build with gcc using MSYS2 but I had to make a few changes because the code appears to rely on a non-standard version of stdlib.h as well as signed time types not available on Windows/MSYS2.

From an MSYS2 terminal in the build directory:

cmake .. .. -DCMAKE_BUILD_TYPE=Release -G "MinGW Makefiles"
mingw32-make

For this to work you must have installed make as follows:

pacman -S mingw64/mingw-w64-x86_64-make

You will now encounter a number of errors. Basically, you'll have to open up the problematic files and fix them. For errors about random() and srandom() not being found, simply redefine them to use rand() and srand(), which use an inferior RNG but whatever:

#define random rand
#define srandom srand

If you get an error about suseconds_t not existing:

typedef long long suseconds_t;

Lastly, in core/contrib/box.c:

1. Comment out the reference to alloca.h
2. Make sure _linux is defined before the ifdef.
3. Replace my_memalign with these two functions:

void *aligned_alloc(size_t align, size_t size)
{
    /* align must be a power of 2 */
    /* size must be a multiple of align */
    if ((align & (align - 1)) || (size & (align - 1)))
    {
        errno = EINVAL;
        return NULL;
    }

#ifdef HAVE_POSIX_MEMALIGN
    if (align < sizeof (void *)) /* POSIX does not allow small alignment */
        align = sizeof (void *);

    void *ptr;
    int err = posix_memalign(&ptr, align, size);
    if (err)
    {
        errno = err;
        ptr = NULL;
    }
    return ptr;

#elif defined(HAVE_MEMALIGN)
    return memalign(align, size);
#elif defined (_WIN32) && defined(__MINGW32__)
    return __mingw_aligned_malloc(size, align);
#elif defined (_WIN32) && defined(_MSC_VER)
    return _aligned_malloc(size, align);
#else
    /* align must be valid/supported */
    assert(align <= alignof (max_align_t));
    return malloc(((void) align, size));
#endif
}


int my_memalign(void** pptr, size_t alignment, size_t size) {
  *pptr = aligned_alloc(alignment, size);
  //*pptr = memalign(alignment, size);
  int fail = (!*pptr);
  return fail;
}

It should compile now. If you then have trouble running the Python apriltags.py demo, make sure it is trying to open the correct libapriltag.dll file. If it complains about missing dependencies there, edit your CMakeLists.txt and add -static like so:

set(EXTRA_FLAGS "-static -Wall -g -march=native ${CMAKE_THREAD_LIBS_INIT}")

This should build a DLL that includes its dependencies statically.

I'm thinking of cleaning this all up and making a PR myself...