Update R and Bioconductor

It’s not a straightforward thing to update R and Bioconductor (a bioinformatics package collection for R), especially if you used the R package that comes with your Linux distribution. For example, the R package from Ubuntu package repository is still 3.5, while the latest version from the r-project site is already 4.0.3. While using an older version of R itself for statistics may not be a problem, many of the Bioconductor packages do have updates and bug fixes that require R v4. And to make things worse, updating Bioconductor itself is a painful process. Below is what I did to update R, Bioconductor, and associated packages. The main lesson learned here is not to use the R package from Ubuntu repository.

1. Remove R installed from the Ubuntu repository;
2. Install R from r-project by adding it as an apt repository;
3. Update R packages (system-wide);
4. Update R packages installed in the user directory;
5. Update BiocManager

sudo apt-get purge r-base* r-recommended r-cran-*
sudo apt autoremove
sudo apt update
sudo add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/'
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
sudo apt update
sudo apt install r-base r-base-core r-recommended r-base-dev

update.packages(ask = FALSE, checkBuilt = TRUE)
if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")
BiocManager::install(version = "3.12")

The R code section may need to run twice once as a sudo user and once as a normal user if you also have packages installed under a user name (that is to say not a system-wide installation from system admin). The last command tells BiocManager (Bioconductor package manager) to install Bioconductor version 3.12 and update all installed Bioconductor pages.