Cross Compiling OpenCV for AArch64

Hei Everybody, I am still trying to crosscompile the whole OpenCV 4 package using the aarch64-gnu toolchain. And i managed to only get one type of errors left in the CmakeErrorLog. I get multiple instances of this Error

fatal error: OpenCL_INCLUDE_DIR-NOTFOUND/CL/cl.h: No such file or directory
2 | #include <OpenCL_INCLUDE_DIR-NOTFOUND/CL/cl.h>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

I was looking into it and went through the cmake files. The Cmakefile should automatically use the right directory and the directory in the cmake file does exit with all the neccesarry .h files. So i dont understand why I would get this error.
Anyone any suggestions ?