Yesterday, I reinstalled R, RStudio and RTools (rtools40) after having some issues with installing packages.
I had previously been working with older versions of R and RStudio. I was able to reinstall all the packages I had before without error messages, including “rstan”. However, when using stan() on a model (and data) that worked perfectly fine before, I now get a warning message:
Warning message: In system(paste(CXX, ARGS), ignore.stdout = TRUE, ignore.stderr = TRUE) : 'C:/PROGRA~1/rtools40/usr/mingw_/bin/g++' not found
The model still seems to run as before but slower.
I have read a bunch of threads about changing the entries in Makevars.win, but I couldn’t get it to work, so I’m starting from scratch and reinstalled everything. The above message is from the fresh reinstall with nothing done to it, not even the configuration of the C++ toolchain, as suggested in the “Getting Started” section.
My first question is if I should even run the configuration of the C++ chain if it’s optional and might cause other problems.
My second question is whether this warning message is a problem at all if the model otherwise seems to work (slower, but works).
I would really appreciate some help and, because I’m not familiar at all with theses issues, I would really appreciate for any potential answer to be explained as if I’m stupid and don’t know anything :) (it will save everyone time).
Here is more information (sorry for the French in the messages):
> sessionInfo() R version 4.0.2 (2020-06-22) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 10 x64 (build 18362) Matrix products: default Random number generation: RNG: Mersenne-Twister Normal: Inversion Sample: Rounding locale:  LC_COLLATE=French_France.1252 LC_CTYPE=French_France.1252 LC_MONETARY=French_France.1252 LC_NUMERIC=C  LC_TIME=French_France.1252 attached base packages:  stats graphics grDevices utils datasets methods base other attached packages:  ghibli_0.3.2 fitdistrplus_1.1-1 survival_3.1-12 rstanarm_2.21.1 Rcpp_1.0.5 arm_1.11-2  lme4_1.1-23 Matrix_1.2-18 MASS_7.3-51.6 reshape2_1.4.4 tidyr_1.1.1 dplyr_1.0.1  shinystan_2.5.0 shiny_1.5.0 rstan_2.21.2 ggplot2_3.3.2 StanHeaders_2.21.0-5 loaded via a namespace (and not attached):  minqa_1.2.4 colorspace_1.4-1 ellipsis_0.3.1 colorRamps_2.3 ggridges_0.5.2 rsconnect_0.8.16  htmlTable_2.0.1 markdown_1.1 base64enc_0.1-3 rstudioapi_0.11 farver_2.0.3 DT_0.14  fansi_0.4.1 codetools_0.2-16 splines_4.0.2 knitr_1.29 shinythemes_1.1.2 bayesplot_1.7.2  Formula_1.2-3 jsonlite_1.7.0 nloptr_126.96.36.199 cluster_2.1.0 png_0.1-7 compiler_4.0.2  backports_1.1.8 assertthat_0.2.1 fastmap_1.0.1 cli_2.0.2 later_188.8.131.52 acepack_1.4.1  htmltools_0.5.0 prettyunits_1.1.1 tools_4.0.2 igraph_1.2.5 coda_0.19-3 gtable_0.3.0  glue_1.4.1 V8_3.2.0 vctrs_0.3.2 nlme_3.1-148 crosstalk_184.108.40.206 xfun_0.16  stringr_1.4.0 ps_1.3.3 mime_0.9 miniUI_0.1.1.1 lifecycle_0.2.0 gtools_3.8.2  statmod_1.4.34 zoo_1.8-8 scales_1.1.1 colourpicker_1.0 promises_1.1.1 parallel_4.0.2  inline_0.3.15 RColorBrewer_1.1-2 prismatic_0.2.0 yaml_2.2.1 curl_4.3 gridExtra_2.3  loo_2.3.1 rpart_4.1-15 latticeExtra_0.6-29 stringi_1.4.6 dygraphs_220.127.116.11 checkmate_2.0.0  boot_1.3-25 pkgbuild_1.1.0 rlang_0.4.7 pkgconfig_2.0.3 matrixStats_0.56.0 lattice_0.20-41  purrr_0.3.4 labeling_0.3 rstantools_2.1.1 htmlwidgets_1.5.1 processx_3.4.3 tidyselect_1.1.0  plyr_1.8.6 magrittr_1.5 R6_2.4.1 generics_0.0.2 Hmisc_4.4-0 pillar_1.4.6  foreign_0.8-80 withr_2.2.0 xts_0.12-0 abind_1.4-5 nnet_7.3-14 tibble_3.0.3  crayon_1.3.4 jpeg_0.1-8.1 grid_4.0.2 data.table_1.13.0 callr_3.4.3 threejs_0.3.3  digest_0.6.25 xtable_1.8-4 httpuv_1.5.4 signal_0.7-6 RcppParallel_5.0.2 stats4_4.0.2  munsell_0.5.0 shinyjs_1.1
> writeLines(readLines(file.path(Sys.getenv("HOME"), ".R/Makevars"))) Error in file(con, "r") : impossible d'ouvrir la connexion De plus : Warning message: In file(con, "r") : impossible d'ouvrir le fichier 'C:\Users\Antoine\Documents/.R/Makevars' : No such file or directory > devtools::session_info("rstan") Error in loadNamespace(name) : aucun package nommé ‘devtools’ n'est trouvé
Thank you very much for any help.