CMake FetchContent fails to install oneTBB

[VincentRouvreau]

I tried to install oneTBB with cmake FetchContent feature with these few lines of CMake:

cmake_minimum_required(VERSION 3.11)
project(cmake_fetch_content_onetbb VERSION 0.0)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)

include(FetchContent)
FetchContent_Declare(
  tbb
  GIT_REPOSITORY https://github.com/oneapi-src/oneTBB.git
  GIT_TAG v2021.12.0
  GIT_SHALLOW ON
)
FetchContent_MakeAvailable(tbb)

add_executable(one_tbb_example src/one_tbb_example.cpp)
target_link_libraries(one_tbb_example TBB::tbb)

But when I launch the CMake command in a fresh conda environment where only cmake is installed:

mkdir build; cd build; cmake -DCMAKE_PREFIX_PATH=$CONDA_PREFIX ..

-- The C compiler identification is GNU 11.4.0                                                                                                                                
-- The CXX compiler identification is GNU 11.4.0                                                                                                                              
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Checking for one of the modules 'hwloc'
-- Looking for getcontext
-- Looking for getcontext - found
-- IPO enabled
-- HWLOC target HWLOC::hwloc_1_11 doesn't exist. The tbbbind target cannot be created
-- HWLOC target HWLOC::hwloc_2 doesn't exist. The tbbbind_2_0 target cannot be created
-- HWLOC target HWLOC::hwloc_2_5 doesn't exist. The tbbbind_2_5 target cannot be created
-- Configuring done (14.0s)
-- Generating done (0.0s)
-- Build files have been written to: /workspace/cmake_fetch_content_onetbb/build

I had a quick look on your installation guidelines, but the dependency to hwloc is not mentioned.

By the way, I fixed the compilation issue by installing hwloc: conda install -c conda-forge libhwloc.

[dnmokhov]

Hi @VincentRouvreau,

Thank you for submitting this. Hwloc is not a required dependency for oneTBB but is optional (if you need Hybrid CPU and NUMA Support).

Please see the Build System Description for more details.