The sf package requires certain system libraries, particularly for handling spatial data. Depending on your operating system, you'll need to install these:
No action needed
sudo apt-get install libgdal-dev libgeos-dev libproj-dev
brew install gdal geos proj
install.packages("devtools")
library(devtools)
install.packages(c("rnaturalearth", "sf", "units", "Rcpp"))
library(rnaturalearth)
library(sf)
library(units)
library(Rcpp)
devtools::install_github("ClaudHGE/palat")
library(palat)