EDIT: My OS is 10.15.4 and R is 4.0.0 and Xcode 11.4.1
I tried to install an archived package "OC" (Optimal Classification). I downloaded the file from here (oc_1.01.tar.gz) first and store it on my desktop. I have tried to install this through install.packages("oc_1.01.tar.gz", repo=NULL, type="source") or install_version("oc", version = "1.01", repos = "https://cran.r-project.org/") and it always failed with warnings as:
ld: warning: directory not found for option '-L/usr/local/gfortran/lib/gcc/x86_64-apple-darwin18/8.2.0'ld: warning: directory not found for option '-L/usr/local/gfortran/lib'ld: warning: directory not found for option '-L/usr/local/gfortran/lib/gcc/x86_64-apple-darwin18/8.2.0'ld: warning: directory not found for option '-L/usr/local/gfortran/lib'ld: library not found for -lgfortranclang: error: linker command failed with exit code 1 (use -v to see invocation)make: *** [oc.so] Error 1ERROR: compilation failed for package ‘oc’* removing ‘/Library/Frameworks/R.framework/Versions/4.0/Resources/library/oc’Error: Failed to install 'unknown package' from URL: (converted from warning) installation of package ‘/var/folders/yv/gzy_ljk971d4jnlntnfvht_40000gn/T//Rtmpr8pJmf/remotes1e1745dfa9dc/oc’ had non-zero exit statusI have tried several solutions similar to this to download gcc or gcc@8 through Homebrew and made changes on the file Makeconf. However, as long as I made changes (even I restored the original codes), installation still fails and returns warnings as:
R clang: error: no such file or directory: 'SHLIB_LIBADD'R clang: error: no such file or directory: '='If I changed CC, CXX (including all CXX related such as CXX17), and FLIBS to gcc-8 or gcc-9, the returned warnings become:
R gcc-8: error: no such file or directory: 'SHLIB_LIBADD'R gcc-8: error: no such file or directory: '='I appreciate any help.