complete build.md

[YanxingLiu]

Motivation

The earlier version of the build.md file lacked essential commands and prompts, leading to compilation errors. As a reuslt,
I've simply refined build.md.

Modification

docs/en/build.md
docs/zh-cn/build.md

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit tests to ensure the correctness.
3. If the modification has a dependency on downstream projects of a newer version, this PR should be tested with all supported versions of downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[lvhan028]

I don't think building nccl from source is a good idea since there are prebuilt libraries.
Do you have any trouble installing nccl directly?
If so, we can discuss about it.

[YanxingLiu]

I don't think building nccl from source is a good idea since there are prebuilt libraries. Do you have any trouble installing nccl directly? If so, we can discuss about it.

Directly install pre-compiled nccl is also is also possible, but previous environments NCCL_ROOT_DIR and NCCL_LIBRARIES seem to use the source-compiled nccl (since the pre-compiled nccl doesn't contain a build folder).
As a result, if I use pre-compiled nccl, the enviroments of nccl should be modified. I'll be submitting a version with pre-compiled nccl later.

[YanxingLiu]

I don't think building nccl from source is a good idea since there are prebuilt libraries. Do you have any trouble installing nccl directly? If so, we can discuss about it.

I have submitted a new version of document. Perhaps the author of the original documentation used the source compilation. So the environment variable needs to include the build folder, but pre-compiled nccl does not include the build folder. So simply removing build in NCCL_ROOT_DIR and NCCL_LIBRARIES will work!

[zhyncs]

So the environment variable needs to include the build folder, but pre-compiled nccl does not include the build folder. So simply removing build in NCCL_ROOT_DIR and NCCL_LIBRARIES will work!

ref to

lmdeploy/builder/manywheel/scripts/install_cuda.sh

Lines 25 to 33 in 8b1b509

	# NCCL license: https://docs.nvidia.com/deeplearning/nccl/#licenses
	mkdir tmp_nccl && cd tmp_nccl
	wget -q https://developer.download.nvidia.com/compute/redist/nccl/v2.15.5/nccl_2.15.5-1+cuda11.8_x86_64.txz
	tar xf nccl_2.15.5-1+cuda11.8_x86_64.txz
	cp -a nccl_2.15.5-1+cuda11.8_x86_64/include/* /usr/local/cuda/include/
	cp -a nccl_2.15.5-1+cuda11.8_x86_64/lib/* /usr/local/cuda/lib64/
	cd ..
	rm -rf tmp_nccl
	ldconfig