Cannot find build tools on 4.0

[clabornd]

> library(Rcpp)
> cppFunction('int add(int x, int y, int z) {
+   int sum = x + y + z;
+   return sum;
+ }')
make: *** No rule to make target 'file15e4405b64f6.o', needed by 'sourceCpp_2.dll'.  Stop.
Error in sourceCpp(code = code, env = env, rebuild = rebuild, cacheDir = cacheDir,  : 
  Error 1 occurred building shared library.

WARNING: The tools required to build C++ code for R were not found.

Please download and install the appropriate version of Rtools:

http://cran.r-project.org/bin/windows/Rtools/

I installed according to http://cran.r-project.org/bin/windows/Rtools/ and am able to install from source.

> sessionInfo()
R version 4.0.1 (2020-06-06)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18362)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] Rcpp_1.0.4.6

loaded via a namespace (and not attached):
 [1] rstudioapi_0.11   magrittr_1.5      usethis_1.6.1     devtools_2.3.0    pkgload_1.1.0     R6_2.4.1          rlang_0.4.6      
 [8] fansi_0.4.1       tools_4.0.1       pkgbuild_1.0.8    sessioninfo_1.1.1 cli_2.0.2         withr_2.2.0       ellipsis_0.3.1   
[15] remotes_2.1.1     assertthat_0.2.1  digest_0.6.25     rprojroot_1.3-2   crayon_1.3.4      processx_3.4.2    callr_3.4.3      
[22] fs_1.4.1          ps_1.3.3          testthat_2.3.2    memoise_1.1.0     glue_1.4.1        compiler_4.0.1    desc_1.2.0       
[29] backports_1.1.7   prettyunits_1.1.1

[eddelbuettel]

That is not an Rcpp issue. It is an issue in your setup. See the CRAN status pages with its two Windows builds which are just fine.

[ShotaOchi]

The code works fine on R 4.0.1 for Windows.
I guess you forgot to put Rtools on PATH.
You can check whether Rtools is on PATH by running the code below.

Sys.which("make")

Rtools isn't on PATH if Sys.which("make") doesn't return the path.

[clabornd]

@ShotaOchi Rtools is being recognized by R. The below is output using the rstudio installed version of rtools, but I've tried the installation from http://cran.r-project.org/bin/windows/Rtools/ as well (and set the path/checked the below output points to C:\rtools40\...) and the error persists.

I suspected it was probably something with my setup, posted here as a last resort, thanks anyway.

> Sys.which('make')
                                   make 
"C:\\RBUILD~1\\4.0\\usr\\bin\\make.exe" 
> Sys.which("gcc.exe")
                                   gcc.exe 
"C:\\RBUILD~1\\4.0\\mingw64\\bin\\gcc.exe" 
> Sys.which("g++.exe")
                                     g++.exe 
"C:\\RBUILD~1\\4.0\\mingw64\\bin\\G__~1.EXE" 
> Sys.which("ls.exe")
                               ls.exe 
"C:\\RBUILD~1\\4.0\\usr\\bin\\ls.exe" 

> devtools::find_rtools()
[1] TRUE