[FEA]: Add support for pathfinder.find_bitcode_lib("nccl_device") #1831

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1. rwgk

   added this to the cuda.pathfinder next milestone on Mar 30, 2026
2. rwgk

   self-assigned this

   on Mar 30, 2026
3. rwgk

   added

   P1Medium priority - Should doMedium priority - Should do

   featureNew feature or requestNew feature or request

   on Mar 30, 2026
4. rwgk

   added the

   Enhancement

   issue type on Mar 30, 2026
5. rwgk

   added

   cuda.pathfinderEverything related to the cuda.pathfinder moduleEverything related to the cuda.pathfinder module

   on Mar 30, 2026
6. rwgk commented on Mar 30, 2026

   

   rwgk

   on Mar 30, 2026

   ContributorAuthor

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   Hi @sb17v, sorry I'm getting to this only now.

   I think this should be easy, and I already looked around while working on #1821 (nvshmem_device.bc), but I couldn't find any released libnccl_device.bc anywhere, even with help from Cursor.

   I did find this:

   smc120-0009.ipp2a2.colossus.nvidia.com:/wrk/clone/nccl $ git remote -v
   origin  https://github.com/NVIDIA/nccl.git (fetch)
   origin  git@github.com:NVIDIA/nccl.git (push)
   
   smc120-0009.ipp2a2.colossus.nvidia.com:/wrk/clone/nccl $ git log -n 1
   commit 49839dfde34086ee9aaf9a1c69ae3404f13773e7 (HEAD -> master, origin/master, origin/HEAD)
   Author: Mark Santesson <msantesson@nvidia.com>
   Date:   Fri Mar 20 23:27:52 2026 +0000
   
       contrib/nccl_ep updates
   
       Fix nccl_ep cuda shim to only get used for CUDA version below 13.1
   
       use __forceinline__ to enable nccl_ep compilation with CUDA 12.8
   
       Fix EP README Common Scenarios tables and tensor classifications
   
   smc120-0009.ipp2a2.colossus.nvidia.com:/wrk/clone/nccl $ git grep libnccl_device.bc
   bindings/ir/CMakeLists.txt:set(UNOPTIMIZED_BC ${OBJDIR}/libnccl_device.bc.unoptimized)
   bindings/ir/CMakeLists.txt:set(OPTIMIZED_BC ${OBJDIR}/libnccl_device.bc.optimized)
   bindings/ir/CMakeLists.txt:set(FINAL_BC ${LIBDIR}/libnccl_device.bc)
   bindings/ir/Makefile:UNOPTIMIZED_BC := $(OBJDIR)/libnccl_device.bc.unoptimized
   bindings/ir/Makefile:OPTIMIZED_BC := $(OBJDIR)/libnccl_device.bc.optimized
   bindings/ir/Makefile:FINAL_BC := $(LIBDIR)/libnccl_device.bc
   

   How do people usually install libnccl_device.bc?

   • PyPI?
   • Conda?
   • Linux distro (e.g. apt)?
   • tarball?

   Could you please help with installation instructions? I think I can figure it out from there.
7. rwgk

   modified the milestones: cuda.pathfinder next, cuda.pathfinder backlog on Apr 3, 2026
8. rwgk

   removed

   P1Medium priority - Should doMedium priority - Should do

   on Apr 3, 2026
9. rwgk commented on Apr 3, 2026

   

   rwgk

   on Apr 3, 2026

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   @sb17v I moved this issue to the backlog while waiting for your feedback.
10. rparolin

    modified the milestones: cuda.pathfinder backlog, cuda.pathfinder next on Apr 8, 2026
11. rwgk

    closed this as completedin #1975on Apr 25, 2026