Mac OS X R error “ld: warning: directory not found for option”

Question

I am trying to install an R package from source, but getting an error:

* installing *source* package ‘mclust’ ...
** package ‘mclust’ successfully unpacked a         


        

Answer 1

Incorporating previous solutions with additional help from the comments, the following solution has worked for me on Mac OS X High Sierra.

Create/edit ~/.R/Makevars with the following contents:

VER=-8
CC=gcc$(VER)
CXX=g++$(VER)
CXX11=g++$(VER)
CXX14=g++$(VER)
CXX17=g++$(VER)
CFLAGS=-mtune=native -g -O2 -Wall -pedantic -Wconversion
CXXFLAGS=-mtune=native -g -O2 -Wall -pedantic -Wconversion
FLIBS=-L/usr/local/Cellar/gcc/8.2.0/lib/gcc/8

Note, I am using homebrew and have gcc version 8.2.0 installed.