R Packages: Solving a problem using devtools in Windows

In the introduction to his book R packages, Hadley Wickham provides a neat function for making sure that everything is set for writing your own R extensions, by simply running the devtools::has_devel(), which, if all goes well, should evaluate to TRUE.

This did not work out for me and I had to fix this problem on 2 different occasions so I felt I need to share this info in case there are others also stumped by this hurdle.

The fix I found – after a full sweaty day – was in this conversation on GitHub and I would like to break it down very quickly:

1. Make sure you have installed Rtools from CRAN
2. Make sure that Rtools/bin as well as Rtools/MinGW/x64/ are added to your system PATH (if you don’t know how, click here)
3. In addition, it is recommended that you install L_AT_EX (the link is also found on the Rtools page mentioned on No. 1)
4. Run the following lines of code

install.packages("devtools")

library(devtools)

install_github("hadley/devtools")    # to get the latest 'pre-CRAN' package updates

find_rtools()

has_devel()    # output should be TRUE

Like I said, I had this problem on 2 different machines (Windows 7 and 10) and the same fix worked on both of them.

Cheers!