Integration into CMake project does not work since Version 9.x

General discussion
1

I am integrating LVGL as a git submodule into my source tree. The project is based on cmake and I am using lv_conf.h in the main folder. Since the last versions, the integration fails with:

/home/werner/projects/pico-ugfx/lvgl/src/core/../lv_conf_internal.h:59:18: error: #include expects "FILENAME" or <FILENAME>
[build]          #include LV_CONF_PATH                     /* Note: Make sure to define custom CONF_PATH as a string */

Setting of LV_CONF_PATH is in the top level CMakeLists.txt

set(LV_CONF_PATH ${CMAKE_SOURCE_DIR}/lv_conf.h)

and changing to

set(LV_CONF_PATH \"${CMAKE_SOURCE_DIR}/lv_conf.h\")

leads to many other failures like

build] CMake Warning (dev) at /home/werner/projects/pico-ugfx/build/lvgl/CMakeFiles/lvgl.dir/DependInfo.cmake:23:
[build]   Syntax Warning in cmake code at column 13

How can this be solved? In the meanwhile I am modifying lv_conf_internal.h to get the project compiled, but this is no solution as it changes the local lvgl repo. I had never issues with the version v8.x

Any ideas are highly appreciated.

Thanks!

Update:
Changing lv_conf_internal.h to

#define STRINGIFY(x) #x
#define TOSTRING(x) STRINGIFY(x)
/* If lv_conf.h is not skipped, include it. */
#if !defined(LV_CONF_SKIP) || defined(LV_CONF_PATH)
    #ifdef LV_CONF_PATH                           /* If there is a path defined for lv_conf.h, use it */
        //#pragma message(">>>>>> " TOSTRING(LV_CONF_PATH))
        #include TOSTRING(LV_CONF_PATH)                     /* Note: Make sure to define custom CONF_PATH as a string */
    #elif defined(LV_CONF_INCLUDE_SIMPLE)         /* Or simply include lv_conf.h is enabled. */
        #include "lv_conf.h"
    #else
        #include "../../lv_conf.h"                /* Else assume lv_conf.h is next to the lvgl folder. */
    #endif
    #if !defined(LV_CONF_H) && !defined(LV_CONF_SUPPRESS_DEFINE_CHECK)
        /* #include will sometimes silently fail when __has_include is used */
        /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80753 */
        #pragma message("Possible failure to include lv_conf.h, please read the comment in this file if you get errors")
    #endif
#endif

makes the project working perfectly.