tentative fix 2 electric boogaloo

Author: aliceb-nv

ci/build_wheel_libcuopt.sh

@@ -27,16 +27,28 @@ fi
 # Install Protobuf + gRPC (protoc + grpc_cpp_plugin)
 bash ci/utils/install_protobuf_grpc.sh
 
-# The fast MPS parser requires OpenMP 5 symbols from the active GCC toolset. Pin FindOpenMP to
-# that compiler's libgomp instead of the older system runtime on Rocky/RHEL wheel builders.
+# The wheel must link against the active GCC toolset's OpenMP runtime. Rocky/RHEL's system
+# libgomp is older and does not provide the OpenMP 5 symbols required by libcuopt.
 CXX_COMPILER="${CXX:-g++}"
 GOMP_LIBRARY="$("${CXX_COMPILER}" -print-file-name=libgomp.so)"
 if [[ "${GOMP_LIBRARY}" != /* || ! -f "${GOMP_LIBRARY}" ]]; then
     echo "Could not resolve libgomp from ${CXX_COMPILER}: '${GOMP_LIBRARY}'" >&2
     exit 1
 fi
 
-export SKBUILD_CMAKE_ARGS="-DCUOPT_BUILD_WHEELS=ON;-DDISABLE_DEPRECATION_WARNING=ON;-DOpenMP_gomp_LIBRARY:FILEPATH=${GOMP_LIBRARY}"
+if ! readelf --dyn-syms --wide "${GOMP_LIBRARY}" | \
+    grep 'omp_fulfill_event' > /dev/null; then
+    echo "${GOMP_LIBRARY} does not provide omp_fulfill_event" >&2
+    exit 1
+fi
+
+echo "Using OpenMP runtime from ${CXX_COMPILER}: ${GOMP_LIBRARY}"
+
+export SKBUILD_CMAKE_ARGS="\
+-DCUOPT_BUILD_WHEELS=ON;\
+-DDISABLE_DEPRECATION_WARNING=ON;\
+-DOpenMP_gomp_LIBRARY:FILEPATH=${GOMP_LIBRARY};\
+-DCUOPT_OPENMP_RUNTIME_LIBRARY:FILEPATH=${GOMP_LIBRARY}"
 
 # OpenSSL 3 hints for libcuopt's own find_package(OpenSSL).
 #

python/libcuopt/CMakeLists.txt

@@ -15,6 +15,14 @@ project(
   LANGUAGES CXX CUDA
 )
 
+option(CUOPT_BUILD_WHEELS "Configure wheel-specific linkage" OFF)
+set(
+  CUOPT_OPENMP_RUNTIME_LIBRARY
+  ""
+  CACHE FILEPATH
+  "Exact OpenMP runtime to link into wheel binaries"
+)
+
 # Debug: Print CUDA compiler version early
 message(STATUS "=============================================================")
 message(STATUS "libcuopt: CMAKE_CUDA_COMPILER_VERSION = ${CMAKE_CUDA_COMPILER_VERSION}")
@@ -69,6 +77,39 @@ target_link_libraries(cuopt_cli PRIVATE
     argparse
 )
 
+if(CUOPT_BUILD_WHEELS)
+  if(NOT IS_ABSOLUTE "${CUOPT_OPENMP_RUNTIME_LIBRARY}" OR
+     NOT EXISTS "${CUOPT_OPENMP_RUNTIME_LIBRARY}")
+    message(
+      FATAL_ERROR
+      "CUOPT_OPENMP_RUNTIME_LIBRARY must name an existing absolute library"
+    )
+  endif()
+
+  message(
+    STATUS
+    "Wheel OpenMP runtime: ${CUOPT_OPENMP_RUNTIME_LIBRARY}"
+  )
+
+  # Keep the exact OpenMP runtime attached even when the executable's only
+  # reference to it comes through libcuopt.so.
+  foreach(_target IN ITEMS cuopt cuopt_cli cuopt_grpc_server)
+    if(TARGET ${_target})
+      target_link_libraries(
+        ${_target}
+        PRIVATE
+        "-Wl,--no-as-needed"
+        "${CUOPT_OPENMP_RUNTIME_LIBRARY}"
+        "-Wl,--as-needed"
+      )
+    endif()
+  endforeach()
+
+  # Report unresolved runtime symbols while linking libcuopt.so rather than
+  # deferring the failure until cuopt_cli or cuopt_grpc_server is linked.
+  target_link_options(cuopt PRIVATE "LINKER:-z,defs")
+endif()
+
 set(rpaths
   "$ORIGIN/../lib64"
   "$ORIGIN/../../rapids_logger/lib64"