The book samples don't build with latest oneAPI toolkits due to missing level zero headers in basic toolkit

[jaynu2]

jay@jayp2:/opt/intel/oneapi$ ls
2025.2 ccl compiler debugger dnnl dpl ippcp mkl mpi pti support.txt tcm vtune
advisor common dal dev-utilities dpcpp-ct ipp licensing modulefiles-setup.sh oneapi-base-toolkit setvars.sh tbb umf
jay@jayp2:/opt/intel/oneapi$ find . -name "ze_api.h"
jay@jayp2:/opt/intel/oneapi$

level_zero seems to be missing from all the toolkits...
https://www.intel.com/content/www/us/en/developer/tools/oneapi/toolkits.html

jay@jayp2:~/dpcpp/level-zero$ find . -name "ze_api.h"
./build/_CPack_Packages/Linux/DEB/level-zero-1.24.1-Linux/level-zero-devel/opt/intel/level_zero/include/level_zero/ze_api.h
./include/ze_api.h

I can find it in the level zero sources, and can build and install it, but it is not clear how to tell cmake to use it. Some online docs suggested defining L0_INCLUDE_DIR and L0_LIBRARY, as I've done here, but that didn't work. Any suggestions for a work-around?

cmake .. -DL0_INCLUDE_DIR=opt/intel/level_zero/include/level_zero -DL0_LIBRARY=/opt/intel/level_zero/lib

[bashbaug]

Hi! Yes, you are correct that the Level Zero headers an libs are distributed separately. Here are a couple of options to get you building again:

1. Set the CMake variable NOL0 to TRUE, which disables the interop samples that require the Level Zero headers and libs. Note that all other samples will continue to work and may still use Level Zero devices even without the headers, and that NOL0 is TRUE by default to minimize dependencies.
2. Install the Level Zero headers and libs from your OS package manager or build from source and install into a standard install location, in which case CMake should find it with no additional steps needed.
3. Build from source, install to an arbitrary directory, and then use CMAKE_INSTALL_PREFIX CMAKE_PREFIX_PATH to point CMake to your install directory.

[jaynu2]

Ok, I presumed I needed to do option 3, and I used the CMAKE_INSTALL_PREFIX for installing the Level Zero build. It isn't obvious that the same CMAKE_INSTALL_PREFIX cmake option can be used with the dpc++ samples build to have it locate the Level Zero build. Are you suggesting modifying something else in the samples cmake configuration files to hard-code in the Level Zero install location?

[bashbaug]

Oops, sorry about that, I meant to say to use CMAKE_PREFIX_PATH to point CMake to your install directory, not CMAKE_INSTALL_PREFIX. I've edited my response above.

It actually doesn't look like this is going to work, though, because we aren't using find_package or find_library or similar to find the Level Zero headers and libraries. We can fix this, but in the meantime, will (1) or (2) work for you?

You may also be able to cobble something together using CPATH or C_INCLUDE_PATH and LIBRARY_PATH, but it will depend on your compiler and it's not something I have tested.

[jaynu2]

I added CPATH and LD_LIBRARY_PATH exports in setup.sh in order to use the newer level_zero. This worked ok, although there were initially many SYCL related deprecation warnings, which the -w compile option hides.

source /opt/intel/oneapi/setvars.sh
source /opt/intel/oneapi/2025.2/oneapi-vars.sh
export CC=icx
export CXX=icpx
export LD_LIBRARY_PATH="/opt/intel/level_zero/lib:/opt/intel/oneapi/2025.2/lib:$LD_LIBRARY_PATH"
export CPATH="/opt/intel/level_zero/include:/opt/intel/oneapi/2025.2/include"

then:
add line to disable warnings near the top of data-parallel-CPP/CMakeLists.txt:
add_compile_options(-w)
I added it immediately after the cmake_minimum_required line. It disables warnings for the entire build.

mkdir build
cd build
cmake ../data-parallel-CPP/
make -j