Hello,
At the moment, Source/GmmLib/CMakeLists.txt calls
set(GMMLIB_API_PATCH_VERSION PATCH_VERSION)
if GMMLIB_API_PATCH_VERSION has not been explicitly defined. This results in the shared library being named literally "libigdgmm.so.9.0.PATCH_VERSION".
The simplest way of fixing this seems to be to change the aforementioned assignment to
set(GMMLIB_API_PATCH_VERSION "${PATCH_VERSION}")