O2 building fails on Ubuntu 20.04 compiling Clang

I’m trying to build O2 from scratch on Ubuntu 20.04. I followed the instruction, installed all the prerequisites, etc. and aliDoctor also says my system it’s ready to build O2.

The build fails during the Clang compilation. It looks like it is trying to install llvm in the wrong directory and a permission error is rise up.
Full log here: log.txt

Has anyone ever seen the issue?