Environment variables

Here are the environment variables CuPy uses.

CUDA_PATH Path to the directory containing CUDA. The parent of the directory containing nvcc is used as default. When nvcc is not found, /usr/local/cuda is used. See Working with Custom CUDA Installation for details.
CUPY_CACHE_DIR Path to the directory to store kernel cache. ${HOME}/.cupy/kernel_cache is used by default. See Overview for details.
CUPY_CACHE_SAVE_CUDA_SOURCE If set to 1, CUDA source file will be saved along with compiled binary in the cache directory for debug purpose. It is disabled by default. Note: source file will not be saved if the compiled binary is already stored in the cache.
CUPY_DUMP_CUDA_SOURCE_ON_ERROR If set to 1, when CUDA kernel compilation fails, CuPy dumps CUDA kernel code to standard error. It is disabled by default.

For install

These environment variables are only used during installation.

CUDA_PATH See the description above.
NVCC Define the compiler to use when compiling CUDA files.