Building out of the box IMB 2021.10 with out of the box oneapi 2025.2.0 with set compilers fails

Download and install oneapi 2025.2.0
Download and untar IMB-2021.10
remove the -Werror from src_cpp/Makefile lines 63 and 64
source intel/oneapi/2025.2.0/setvars.sh
cd to imb folder
run "make CC="/path/to/intel/oneapi/2025.2.0/mpi/2021.16/bin/mpiicc -cc=/path/to/intel/oneapi/2025.2.0/compiler/2025.2/bin/icx" CXX="/path/to/intel/oneapi/2025.2.0/mpi/2021.16/bin/mpiicpc -cxx=/path/to/intel/oneapi/2025.2.0/compiler/2025.2/bin/icpx" all

Fails with:
/usr/bin/ld: MT/MT_benchmark.o:/path/to/mpi-benchmarks-IMB-v2021.10/src_cpp/MT/MT_benchmark.h:254: more undefined references to `omp_get_thread_num' follow
icpx: error: linker command failed with exit code 1 (use -v to see invocation)

If you try to build with "make -j all" it passes. The build only fails when sourcing the oneapi setvars.sh and then building with explicitly set compilers.
This is also assuming the fix from #66 of removing the -Werror from lines 63 and 64 in src_cpp/Makefile

Am I setting the wrong compilers?