Could not build (add_custom_target)

[cmakelabs]

While trying to build, I encountered this issue, and could not figure out what could be the reason:

Call Stack (most recent call first):
  /usr/src/googletest/googletest/CMakeLists.txt:91 (include)
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Error at CMakeLists.txt:41 (add_custom_target):
  Cannot find source file:

    /home/noetic/rio_reve_ws/src/rio/x_rio/cfg/cfg_radar_ego_velocity_estimation

  Tried extensions .c .C .c++ .cc .cpp .cxx .cu .mpp .m .M .mm .ixx .cppm
  .ccm .cxxm .c++m .h .hh .h++ .hm .hpp .hxx .in .txx .f .F .for .f77 .f90
  .f95 .f03 .hip .ispc


CMake Generate step failed.  Build files cannot be regenerated correctly.
cd /home/noetic/rio_reve_ws/build/x_rio; catkin build --get-env x_rio | catk

May you please tell me what could be the workaround, I am quite interested in trying this package