docker-python: [BUG] Exception: Your CUDA environment is invalid.

Recently I got this error while trying to install cupy on a Kaggle GPU Kernel:

Collecting cupy
  Downloading cupy-7.4.0.tar.gz (3.7 MB)
     |████████████████████████████████| 3.7 MB 3.4 MB/s eta 0:00:01
    ERROR: Command errored out with exit status 1:
     command: /opt/conda/bin/python3.7 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-jzxcfeco/cupy/setup.py'"'"'; __file__='"'"'/tmp/pip-install-jzxcfeco/cupy/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-install-jzxcfeco/cupy/pip-egg-info
         cwd: /tmp/pip-install-jzxcfeco/cupy/
    Complete output (48 lines):
    Options: {'package_name': 'cupy', 'long_description': None, 'wheel_libs': [], 'wheel_includes': [], 'no_rpath': False, 'profile': False, 'linetrace': False, 'annotate': False, 'no_cuda': False, 'use_hip': False}
    
    -------- Configuring Module: cuda --------
    cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
    cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
    /opt/conda/compiler_compat/ld: /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/libcuda.so: file not recognized: file truncated
    collect2: error: ld returned 1 exit status
    Cannot build a stub file.
    Original error: command 'g++' failed with exit status 1
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-jzxcfeco/cupy/setup.py", line 129, in <module>
        ext_modules = cupy_setup_build.get_ext_modules()
      File "/tmp/pip-install-jzxcfeco/cupy/cupy_setup_build.py", line 744, in get_ext_modules
        extensions = make_extensions(arg_options, compiler, use_cython)
      File "/tmp/pip-install-jzxcfeco/cupy/cupy_setup_build.py", line 492, in make_extensions
        raise Exception('Your CUDA environment is invalid. '
    Exception: Your CUDA environment is invalid. Please check above error log.
    
    ************************************************************
    * CuPy Configuration Summary                               *
    ************************************************************
    
    Build Environment:
      Include directories: ['/usr/local/cuda/include']
      Library directories: ['/usr/local/cuda/lib64']
      nvcc command       : ['/usr/local/cuda/bin/nvcc']
    
    Environment Variables:
      CFLAGS          : (none)
      LDFLAGS         : (none)
      LIBRARY_PATH    : (none)
      CUDA_PATH       : (none)
      NVTOOLSEXT_PATH : (none)
      NVCC            : (none)
      ROCM_HOME       : (none)
    
    Modules:
      cuda      : No
        -> Cannot link libraries: ['cublas', 'cuda', 'cudart', 'cufft', 'curand', 'cusparse', 'nvrtc']
        -> Check your LDFLAGS environment variable.
    
    ERROR: CUDA could not be found on your system.
    Please refer to the Installation Guide for details:
    https://docs-cupy.chainer.org/en/stable/install.html
    
    ************************************************************
    
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.