error -- unsupported GNU version! gcc versions later than 7 are not supported! about xmrig-cuda

[bdytx5]

this will help you change versions of gcc and g++ easily https://linuxconfig.org/how-to-switch-between-multiple-gcc-and-g-compiler-versions-on-ubuntu-20-04-lts-focal-fossa

[Spudz76]

You have told it to use the gcc-8 as host compiler where CUDA 9.2 only supports gcc-7 maximum

Try:

cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON\
-DCUDA_VERBOSE_BUILD=ON\
-DCUDA_LIB=/usr/lib/x86_64-linux-gnu/nvidia/current/libcuda.so\
-DCUDA_TOOLKIT_ROOT_DIR=/usr/lib/x86_64-linux-gnu/nvidia/current\
-DCMAKE_C_COMPILER=gcc-7 -DCMAKE_CXX_COMPILER=g++-7
make -j$(nproc)

Or much more simply:

CC=/usr/bin/gcc-7 CXX=/usr/bin/g++-7 cmake .. -DCMAKE_VERBOSE_MAKEFILE=ON\
-DCUDA_VERBOSE_BUILD=ON\
-DCUDA_TOOLKIT_ROOT_DIR=/usr/lib/x86_64-linux-gnu/nvidia/current
make -j$(nproc)