R not recognizing GSL library undefined references
问题 I am installing a package from github in R (link here: https://github.com/aliceyiwang/mvabund), using devtools. I have installed Rtools, using the instructions for another package (here: https://cran.r-project.org/web/packages/dynr/vignettes/InstallationForUsers.pdf) and all the checks there indicate that GSL and RTools are installed properly. I've set the Windows system environment variables LIB_GSL (as "C:/R/local323" ) and PATHS (as "C:/RTools/bin/", "C:/RTools/mingw_64/bin", "C:/R/R-3.5.1