Grextras installation issue

I am trying to install grextras from git. The normal git link

GitHub - guruofquality/gras: GRAS: The GNU Radio Advanced Scheduler

is not working. So sylvain provided an old git repository which i
downloaded and tried to build. I am getting the following error

anrc@anrc-S5000XVN:~/Downloads/grextras-08a5747bff911f3c8722224d3d2a4f2f8fa68b10/build$
cmake …/
– The CXX compiler identification is GNU
– The C compiler identification is GNU
– Check for working CXX compiler: /usr/bin/c++
– Check for working CXX compiler: /usr/bin/c++ – works
– Detecting CXX compiler ABI info
– Detecting CXX compiler ABI info - done
– Check for working C compiler: /usr/bin/gcc
– Check for working C compiler: /usr/bin/gcc – works
– Detecting C compiler ABI info
– Detecting C compiler ABI info - done
CMake Error at CMakeLists.txt:34 (include):
include could not find load file:

GRASTool

– checking for module ‘volk’
– found volk, version 0.1
– Found VOLK: /usr/local/lib/libvolk.so
CMake Error at math/CMakeLists.txt:20 (GRAS_TOOL):
Unknown CMake command “GRAS_TOOL”.

– Configuring incomplete, errors occurred!

I checked the mailing list for similar errors. There was one answer to
install 3.6. But i am running it on gnuradio 3.6.3. So that is not the
issue. what is the problem? kindly help