gcc from home:marxin:gcc8-incubator project
Select Your Operating System
Add repository and install manually
For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:marxin:gcc8-incubator/openSUSE_Tumbleweed/home:marxin:gcc8-incubator.repo zypper refresh zypper install gcc