I'm also currently running an older version of Rstudio (Version 1.1.463) as my mac is running El Capitan (not enough memory to update). When trying to install and run 'tidymodels' I receive:
Error: package or namespace load failed for ‘tidymodels’ in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]): there is no package called ‘rstanarm’
I have then attempted to install 'rstanarm' and receive:
Package which is only available in source form, and may need compilation of
C/C++/Fortran: ‘rstanarm’
Do you want to attempt to install these from sources? (Yes/no/cancel)
Following any of these options is unsuccessful. Is it possible to use 'tidymodels' given my situation?