Debugging C++ code of an R package with Rcpp using gdb cannot print variable value with R_PV (unknown return type)

Question

I have used RStudio on Ubuntu 18.04 to create an hello world R package using Rcpp like described here in Rcpp Package Development:

My ~/.R/Makevars contain

Answer 1

(gdb) p R_PV(x)

In my R source, R_PV is a function returning void. Try this instead:

(gdb) call R_PV(x)

As Dirk Eddelbuettel noted, you still need to pass the right type to R_PV, so perhaps the correct command is:

(gdb) call R_PV(Rcpp::wrap(&x))