This script creates the automated GNU Guix channel for CRAN packages and the automated GNU Guix channel for Bioconductor packages. Since Guix commit c329eeb3a8a87edfa21675ce67353778a3b24773 you can run it like this:
REPO=https://github.com/guix-science/guix-cran
# REPO=https://github.com/guix-science/guix-bioc
git clone $REPO output
mkdir -p cache/{description,contents}
guix repl import.scm output [guix-cran|guix-bioc] [cran|bioc]
The directory output will contain the updated channel if the import
succeeded.