Is it impossible to install R 4.0 on Ubuntu 18.04.4 LTS because r-base-core requires a libc6 version >= 2.29?

I am using Ubuntu 18.04, for this there should be a single source deb bionic-cran40/ in /etc/apt/sources.list Unfortunately, I added deb focal-cran40/ by mistake which I removed to install R 4.0 R is successfully installed now.

The problem may to be with your /etc/apt/sources.list. Please check whether you have disabled all other repositories for R in there, e.g. it should not contain lines like deb bionic-cran35/

Question: Is your system otherwise current to 18.04? If so, the upgrade should just work. I wrote a blog post (prior to the release) about testing R 4.0.0 on 18.04 along with a video:

  • blog post
  • slides with links
  • video showing the upgrade

Two more recent (related) posts at as well.

In short, on a system that is otherwise well (i.e. no other packages forced or conflicts or what have you), one just adds the new repo (shown in slides and video), updates the apt index and upgrades. I have done the same for my 19.10 Ubuntu system in another video.