search for: check_compil

...ls(debug = TRUE) Found in Rtools 4.3 installation folder [1] TRUE > check_rtools(debug = TRUE) Found in Rtools 4.3 installation folder [1] TRUE > has_compiler(debug = TRUE) Trying to compile a simple C file Running "C:/PROGRA~1/R/R-43~1.1/bin/x64/Rcmd.exe" SHLIB foo.c [1] FALSE > check_compiler(debug = TRUE) Trying to compile a simple C file Running "C:/PROGRA~1/R/R-43~1.1/bin/x64/Rcmd.exe" SHLIB foo.c Error: Failed to compile C code > rcmd_build_tools() Error in paste0("R CMD ", ..1) : the ... list contains fewer than 1 element In addition: Warning messages: 1...

TL:DR there are at least three maybe four ways to address this depending on what you plan to do. I usually adjust PATH to add Rtools using .Rprofile. But if you do that then if you want to use the command line to invoke R then you need to set the PATH separately when you start the shell. For this reason some people like to set it in the User Environment Variables control panel... but some Rtools