Following Installing NCCL I install NCCL:

sudo apt install libnccl2=2.4.2-1+cuda10.0 libnccl-dev=2.4.2-1+cuda10.0

But I can't find nccl.h.

After I install NCCL, where is nccl.h?

  • 3
  • "But I can't find nccl.h" but you forgot how you search for it.
    – Rinzwind
    Apr 17, 2019 at 18:45
  • locate nccl.h doesn't find it. find . -name 'nccl.h' will take way too long starting from the root, especially taking into account the /mnt directories.
    – empty
    Apr 17, 2019 at 18:54
  • You can add -xdev to prevent find from descending into other mounted filesystems. You can likely also root the search at /usr/include instead of /. Apr 17, 2019 at 19:28
  • @empty locate is not updated immediately. you need to rebuild the database if you want newly added files from that.
    – Rinzwind
    Apr 17, 2019 at 20:27

1 Answer 1


This worked:

sudo dpkg-query -L libnccl-dev
  • 1
    Yes this hleped me too. Ubuntu 18.04
    – JAV
    Oct 22, 2020 at 13:03

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