Troubleshooting
libGl.so
Failed linking against libGL.so:
/usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/../../../../lib64/libGL.so: undefined reference to `_glapi_tls_Current'
collect2: error: ld returned 1 exit status
Solution:
emerge --nodeps -1 nvidia-drivers
Do above first, then continue.
External resources