leezu commented on a change in pull request #17297: Fix NCCL Cmake autodetect issue URL: https://github.com/apache/incubator-mxnet/pull/17297#discussion_r367715337
########## File path: cmake/Modules/FindNCCL.cmake ########## @@ -33,6 +33,23 @@ set(NCCL_ROOT_DIR "" CACHE PATH "Folder contains NVIDIA NCCL") +# first check in the /usr/local/cuda before other paths Review comment: @ChaiBapchya Thank you! After reading CMP0074 again, > [...] now searches prefixes specified by the `<PackageName>_ROOT` CMake variable and the `<PackageName>_ROOT` environment variable. Package roots are maintained as a stack so nested calls to all find_* commands inside find modules and config packages also search the roots as prefixes. seems to imply that it's not necessary to list `NCCL_ROOT` as part of `find_path` and `find_library`, but rather it's done automatically. Do you understand it in the same way? Also https://cmake.org/cmake/help/latest/command/find_package.html#search-procedure (paragraph "The set of installation prefixes is constructed using the following steps [...]") suggests this. If so, `set(NCCL_ROOT $ENV{NCCL_ROOT} CACHE PATH "Folder contains NVIDIA NCCL")` would be superfluous. Also it seems none of the other Find modules check the `X_LIB_DIR` and `X_LIB_DIR` env variables. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
