Linking error

[ignacio-rocco]

Hi, I was getting a linking error during the compilation of the MinkowskiEngineBackend.

++ -pthread -shared -B /anaconda3/envs/pytorch13/compiler_compat -L/anaconda3/envs/pytorch13/lib -Wl,-rpath=/anaconda3/envs/pytorch13/lib -Wl,--no-as-needed -Wl,--sysroot=/ build/temp.linux-x86_64-3.6/pybind/minkowski.o -Lobjs -L/usr/local/cuda-10.1/lib64 -lminkowski -lopenblas -lcudart -o build/lib.linux-x86_64-3.6/MinkowskiEngineBackend.cpython-36m-x86_64-linux-gnu.so
/anaconda3/envs/pytorch13/compiler_compat/ld: cannot find -lm
/anaconda3/envs/pytorch13/compiler_compat/ld: cannot find -lpthread
/anaconda3/envs/pytorch13/compiler_compat/ld: cannot find -lc
collect2: error: ld returned 1 exit status
error: command 'g++' failed with exit status 1

I solved it by adding extra_link_args=['-L/usr/lib/x86_64-linux-gnu/'] to setup.py in the ExtModules section:

    ext_modules=[
        Extension(
            name='MinkowskiEngineBackend',
            include_dirs=['./', get_python_inc() + "/.."],
            sources=[
                'pybind/minkowski.cpp',
            ],
            libraries=[
                'minkowski',
                'openblas',  # for other blas, replace openblas
            ],
            library_dirs=['objs'],
            extra_compile_args=extra_compile_args,
            extra_link_args=['-L/usr/lib/x86_64-linux-gnu/']
        )
    ],

[ignacio-rocco]

This seems to have disappeared on a new environment.