Building ROOT 6.26/06 from source with R bindings enabled on Ubuntu 20.04 or 22.04

Since posting this message, I have found this message. I am seeing if issuing the command

cmake -DCMAKE_INSTALL_PREFIX=../root_install -Drpath=ON -Dr=ON ../root_src

then issuing the command

cmake --build . -- install -j$(nproc)

resolves the issues I have been having on my machine where R was found by cmake. What I am unsure of now though is what @Wile_E_Coyote means when they say

Then execute “make install”, rename the original “<builddir>” (so that the newly installed libraries will NOT find the originals) and try “ldd” on all newly installed libraries.

And how it applies to the steps I am describing above? What would I be renaming? root_build? Does this mean I would temporarily rename root_build to something else, then rename it back after issuing the command

cmake --build . -- install -j$(nproc)

Where would I find the libraries I would need to “ldd”?