What's the problem?

When you try to use sf or geojsonio on a ComputeCanada cluster, you might get an error like this:

-----Error: libudunits2.a not found-----
     If the udunits2 library is installed in a non-standard location,
     use --configure-args='--with-udunits2-lib=/usr/local/lib' for   
     example,
     or --configure-args='--with-udunits2-include=/usr/include/udunits2'
     replacing paths with appropriate values for your installation.
     You can alternatively use the UDUNITS2_INCLUDE and UDUNITS2_LIB
     environment variables.
     If udunits2 is not installed, please install it.
     It is required for this package.
     ERROR: configuration failed for package ‘udunits2’

...

installation of package ‘udunits2’ had non-zero exit status

When this happens, the issue is that you haven't loaded the udunits2 module. You should run the following code before you open R to run your install.packages() command.

module load udunits/2.2.26
module load StdEnv/2020  gcc/9.3.0
module load gdal/3.5.1