gcc9 from home:smarty12:gcc project
Select Your Operating System
Add repository and install manually
For openSUSE Leap 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:smarty12:gcc/openSUSE_Leap_15.4/home:smarty12:gcc.repo zypper refresh zypper install gcc9
For openSUSE Leap 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:smarty12:gcc/openSUSE_Leap_15.3/home:smarty12:gcc.repo zypper refresh zypper install gcc9