openmp wasn't detected on mac with installed llvm and libomp

[yqy6611]

Describe the bug

I have installed llvm and libomp successfully and set configure arguments, yet openmp still couldn't be detected.

Code for Reproduction

install.packages('abess', type = 'source')

Desktop (please complete the following information):

• OS: macOS sonoma
• R Version: 4.4.1
• Package Version: 0.4.9

Screenshots

• installing source package ‘abess’ ...
  ** package ‘abess’ successfully unpacked and MD5 sums checked
  ** using staged installation
  checking whether the C++ compiler works... yes
  checking for C++ compiler default output file name... a.out
  checking for suffix of executables...
  checking whether we are cross compiling... no
  checking for suffix of object files... o
  checking whether the compiler supports GNU C++... yes
  checking whether /opt/homebrew/opt/llvm/bin/clang++ accepts -g... yes
  checking for /opt/homebrew/opt/llvm/bin/clang++ option to enable C++11 features... none needed
  checking how to run the C++ preprocessor... /opt/homebrew/opt/llvm/bin/clang++ -E
  checking for gcc... /opt/homebrew/opt/llvm/bin/clang
  checking whether the compiler supports GNU C... yes
  checking whether /opt/homebrew/opt/llvm/bin/clang accepts -g... yes
  checking for /opt/homebrew/opt/llvm/bin/clang option to enable C11 features... none needed
  checking how to run the C preprocessor... /opt/homebrew/opt/llvm/bin/clang -E
  Spectra library exists.
  Complier code exists in src/ directory. Install R package according to the complier code.
  checking whether OpenMP will work in a package... no
  OpenMP is unavailable on this Mac OSX system. Training speed may be suboptimal.
  To use all CPU cores for training jobs, you should install OpenMP by running

         brew install libomp
  

configure: creating ./config.status
config.status: creating src/Makevars

[yqy6611]

Attached is my ~/.R/Makevars:

CC=/opt/homebrew/opt/llvm/bin/clang
CXX=/opt/homebrew/opt/llvm/bin/clang++
CFLAGS += -Xclang -fopenmp
LDFLAGS += -L/opt/homebrew/opt/libomp/lib -lomp
CPPFLAGS += -I/opt/homebrew/opt/libomp/include

[Mamba413]

@yqy6611 Thanks for the report. It may take some time to fix this issue. However, we’ve found that abess can run quickly without using OpenMP, so you should still be able to use abess as usual for most tasks.

[yqy6611]

@Mamba413 Well noted.