@GaryKT can you confirm that this PR fixes #5401 and #5347 for you as well?

Closing as presumed fixed until hearing otherwise.

@shelhamer I will keep this one open since I would like that fix to go in on windows. There are two fixes in this PR:

1. Getting nccl to correctly load the nvml.dll since it is not on PATH by default. This one is Windows specific.
2. Getting the uid's to work on python3 since python 3 and python 2 handle strings differently. Although I have not tested this change on a UNIX platform I believe the changes could also benefit the master branch.

I tested the first commit about uid and it works, can you remove the second commit so that we can merge?

@cypof I wrote the code in a rush so let me clean it up (I think I can come up with less changes) and then I will resubmit the first commit to master.

@cypof @shelhamer I could simplify the first commit if we use a relatively recent version of boost.

According to the docs we require 1.55 but according to the CMake build we require 1.46, I assume that the docs is more up to date than the CMake build. Am I correct?

I am asking since 1.53 handles the conversion from python strings and bytes to C++ std::string automatically. If we can assume this we only have to convert manually from C++ to python.

See this: https://github.com/boostorg/python/blob/boost-1.53.0/src/converter/builtin_converters.cpp#L381

Part of this was merge in #5527.