[This question is similar to: Rtools not recognized on Win 10, R 3.6.1, RStudio 1.2.5001, but I couldn't find a solution there.]
I'm using R studio version 1.1.442, and a recent installation of R 3.6.3 (2020-02-29), on Windows 7, Platform: x86_64-w64-mingw32/x64.
I also installed Rtools 3.5. Yet, every time I try to build/install a local package I get:
WARNING: Rtools is required to build R packages but is not currently installed. Please download and install the appropriate version of Rtools before proceeding: https://cran.rstudio.com/bin/windows/Rtools/
I've done all the relevant tests I can find, and none point to any problems on my system. At least
pkgbuild can find Rtools. Why can't Rstudio??? Is this a bug of R studio 1.1.442 or one related to R 3.6.3?
> pkgbuild::find_rtools()  TRUE > pkgbuild::find_rtools(debug=TRUE) Scanning R CMD config CC... cc_path: c:/Rtools/mingw_64/bin/gcc install_path: c:/Rtools Found compatible gcc from R CMD config CC  TRUE > pkgbuild::rtools_path()  "c:/Rtools/bin"