I know that binary packages are R-version specific, but it was a bit surprising that Rcpp 1.0.5 built with R-4.0.2 cannot be loaded into R-4.0.0. % R-4.0.0 --quiet
library(Rcpp, lib="lib-4.0.2")
Error: package or namespace load failed for ?Rcpp? in dyn.load(file, DLLpath = DLLpath, ...): unable to load shared object '/tmp/bill/lib-4.0.2/Rcpp/libs/Rcpp.so': /tmp/bill/lib-4.0.2/Rcpp/libs/Rcpp.so: undefined symbol: EXTPTR_PTR In addition: Warning message: package ?Rcpp? was built under R version 4.0.2 It looks like R's include/Rinternals.h was rejiggered so the function EXTPTR_PTR is called when CAR0 used to be. (I think they do the same thing.) Bill Dunlap TIBCO Software wdunlap tibco.com