Update oneMKL git tag to the latest version that support 2025 oneAPI.

[sreerajkksd]

Builds are failing when using current oneMKL from upstream when used in connection with intel oneAPI v2025.0.

The following fixes this:

> git diff
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a5362ec51d..96a9bbdad70 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -117,7 +117,7 @@ if(_use_onemkl_interfaces)
     FetchContent_Declare(
             onemkl_interfaces_library
             GIT_REPOSITORY https://github.com/oneapi-src/oneMKL.git
-            GIT_TAG f2d2dcb4213a435bb60fbb88320c5f24892423ce
+            GIT_TAG 8f4312ef966420b9b8b4b82b9d5c22e2c91a1fe7
     )
     FetchContent_MakeAvailable(onemkl_interfaces_library)
     set(CMAKE_INSTALL_RPATH "${CMAKE_BINARY_DIR}/lib")

Is it only possible to add an additional option to use a local checkout directory of oneMKL instead ?

Use ONEMKL_INTERFACE_DIR=<localdir> cmake option and make the following changes:

> git diff
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a5362ec51d..88219124009 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -114,11 +114,15 @@ if(_use_onemkl_interfaces)
         set(ENABLE_MKLGPU_BACKEND False)
         set(ENABLE_MKLCPU_BACKEND False)
     endif()
-    FetchContent_Declare(
-            onemkl_interfaces_library
-            GIT_REPOSITORY https://github.com/oneapi-src/oneMKL.git
-            GIT_TAG f2d2dcb4213a435bb60fbb88320c5f24892423ce
-    )
+    if(ONEMKL_INTERFACE_DIR)
+        FetchContent_Declare(onemkl_interfaces_library SOURCE_DIR "${ONEMKL_INTERFACE_DIR}")
+    else()
+        FetchContent_Declare(
+                onemkl_interfaces_library
+                GIT_REPOSITORY https://github.com/oneapi-src/oneMKL.git
+                GIT_TAG f2d2dcb4213a435bb60fbb88320c5f24892423ce
+        )
+    endif()
     FetchContent_MakeAvailable(onemkl_interfaces_library)
     set(CMAKE_INSTALL_RPATH "${CMAKE_BINARY_DIR}/lib")
 endif()

Is this change sensible ?

[antonwolfy]

@sreerajkksd , I've created a PR to bump oneMKL version to 0.6 which is compatible with 2025.0 release.
Also it implements a new cmake option DPNP_ONEMKL_INTERFACES_DIR. It can be set through:

python scripts/build_locally.py --onemkl-interfaces --onemkl-interfaces-dir=<onemkl-source-dir> --verbose