Cannot cmake on macOS 12.0.1 on M1 / osx-arm64

[akgerber]

Summary

I am attempting to follow the instructions to build Faiss in: https://github.com/facebookresearch/faiss/blob/main/INSTALL.md

I am unable to produce the Makefile via cmake:

>cmake -B build .
CMake Error at /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find OpenMP_CXX (missing: OpenMP_CXX_FLAGS OpenMP_CXX_LIB_NAMES)
Call Stack (most recent call first):
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindOpenMP.cmake:544 (find_package_handle_standard_args)
  faiss/CMakeLists.txt:217 (find_package)


-- Configuring incomplete, errors occurred!

Platform

OS: macOS 12.0.1
Faiss version: b598f55
CMake version: 3.21.4, installed via Homebrew

Running on:

• CPU
• GPU

Interface:

• C++
• Python

Reproduction instructions

>cmake -B build .
CMake Error at /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find OpenMP_CXX (missing: OpenMP_CXX_FLAGS OpenMP_CXX_LIB_NAMES)
Call Stack (most recent call first):
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindOpenMP.cmake:544 (find_package_handle_standard_args)
  faiss/CMakeLists.txt:217 (find_package)


-- Configuring incomplete, errors occurred!

Note that I do have libopenmp installed:

 brew info libomp
libomp: stable 13.0.0 (bottled)
LLVM's OpenMP runtime library
https://openmp.llvm.org/
/opt/homebrew/Cellar/libomp/13.0.0 (9 files, 1.6MB) *
  Poured from bottle on 2021-11-16 at 15:12:49
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/libomp.rb
License: MIT
==> Dependencies
Build: cmake ✔
==> Analytics
install: 102,098 (30 days), 295,521 (90 days), 1,169,984 (365 days)
install-on-request: 12,866 (30 days), 36,332 (90 days), 140,288 (365 days)
build-error: 1 (30 days)

An identical error occurs if I attempt to specify LLVM clang/clang++ (which support OpenMP):

 > CXX=/opt/homebrew/opt/llvm/bin/clang++ CC=/opt/homebrew/opt/llvm/bin/clang cmake -DFAISS_ENABLE_GPU=OFF -B build .
CMake Error at /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find OpenMP_CXX (missing: OpenMP_CXX_FLAGS OpenMP_CXX_LIB_NAMES)
Call Stack (most recent call first):
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
  /opt/homebrew/Cellar/cmake/3.21.4/share/cmake/Modules/FindOpenMP.cmake:544 (find_package_handle_standard_args)
  faiss/CMakeLists.txt:217 (find_package)

I am successfully able to use homebrew to build/install Faiss (but I would like to produce Python bindings which the Homebrew build does not appear to support):

> brew reinstall faiss --build-from-source
==> Downloading https://github.com/facebookresearch/faiss/archive/v1.7.1.tar.gz
==> Downloading from https://codeload.github.com/facebookresearch/faiss/tar.gz/v1.7.1
##O#-#
==> Reinstalling faiss
==> cmake -B build . -DFAISS_ENABLE_GPU=OFF -DFAISS_ENABLE_PYTHON=OFF -DBUILD_SHARED_LIBS=ON
==> make
==> make install
🍺  /opt/homebrew/Cellar/faiss/1.7.1: 101 files, 2.4MB, built in 10 seconds

[beauby]

Could you provide the complete log of your cmake invocation?

[akgerber]

Thanks for following up, @beauby !

I managed to get some help and worked around this by also specifying pointing the necessary library paths to LLVM clang paths, as well as turning off GPU support:

LDFLAGS="-L/opt/homebrew/opt/llvm/lib" CPPFLAGS="-I/opt/homebrew/opt/llvm/include" CXX=/opt/homebrew/opt/llvm/bin/clang++ CC=/opt/homebrew/opt/llvm/bin/clang cmake -DFAISS_ENABLE_GPU=OFF -B build .

Note LLVM clang can be installed with Homebrew via:

brew install llvm

[ceejatec]

Is it possible this will be corrected such that it does not require an extra compiler toolchain (LLVM) to be installed? Failing that, https://github.com/facebookresearch/faiss/blob/main/INSTALL.md should likely be updated with these instructions, if they are the 'official' approach.

[fdchiu]

I am still having the same issue and the suggested solution does NOT work for me.

[shivam096]

Is there any update on this issue?

[nam178]

Installing openblas and libomp with brew then restart the terminal worked for me