'RcppArmadillo.h' file not found when installing RcppArmadillo from source - r

Question

RcppArmadillo 0.8.400.0.0 works just fine on my computer, both from sourceCpp and cxxfunction. Now I want to upgrade to 0.8.500.0, which requires compilation from source. Then I got the error
ccache /usr/local/clang6/bin/clang++ -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I"/Library/Frameworks/R.framework/Versions/3.5/Resources/library/Rcpp/include" -I/usr/local/include -I/Applications/CPLEX_Studio128/cplex/include -I/Applications/CPLEX_Studio128/concert/include -DIL_STD -fPIC -Wall -g -O2 -c RcppArmadillo.cpp -o RcppArmadillo.o
RcppArmadillo.cpp:22:10: fatal error: 'RcppArmadillo.h' file not found
#include <RcppArmadillo.h>
^~~~~~~~~~~~~~~~~
1 error generated.
I got this error whether I ran install.packages("RcppArmadillo") in RStudio or in R console outside RStudio. My compiler is clang4, and I have no problem installing RcppParallel or compiling my own Rcpp code that uses RcppArmadillo and RcppParallel. R version: 3.5.0, MacOS High Sierra.
Edit: I looked at https://github.com/RcppCore/RcppArmadillo/issues/143, which is very relevant. I did install clang6 and gfortran 6.1, both downloaded from the CRAN website. I also changed the .R/Makevars file to reflect the changes to clang6. I have also installed ccache as suggested, to make compilation faster. Here's my Makevars:
F77 = /usr/local/gfortran/bin/gfortran
FC = $F77
FLIBS=-L/usr/local/gfortran/lib/gcc/x86_64-apple-darwin16/6.3.0 -L/usr/local/gfortran/lib -lgfortran -lquadmath -lm
CC=ccache /usr/local/clang6/bin/clang
SHLIB_CXXLD=ccache /usr/local/clang6/bin/clang++
CXX= ccache /usr/local/clang6/bin/clang++ -Wall
CXX1X= ccache /usr/local/clang6/bin/clang++
CXX98= ccache /usr/local/clang6/bin/clang++
CXX11= ccache /usr/local/clang6/bin/clang++
CXX14= ccache /usr/local/clang6/bin/clang++
CXX17= ccache /usr/local/clang6/bin/clang++
LDFLAGS=-L/usr/local/clang6/lib
From the outputs in the R console when I was installing the package (added to the error message above), I can tell that clang6 was used for compilation. I also found the downloaded RcppArmadillo tarball, unpacked it, and ran ./configure from the command line. Nothing seemed wrong there; no config.log file was generated. This doesn't seem to be a configuration problem. Then I still got the exact same error when trying to install the package in R, after configuration, in libs. I also didn't get any message about -fopenmp. It seems that my problem is a bit different from that in the GitHub ticket.

Answer 1

R 3.5.x requires clang6 and adding clang6 to your system PATH variable.
Steps:
x Download and install the clang-6.0.0.pkg official package from CRAN.
x Delete your ~/.R/Makevars as it is likely set to use clang4. To do this, open Terminal and type:
sudo rm ~/.R/Makevars
x Then add to your ~/.bash_profile the following:
if [ -d "/usr/local/clang6/bin" ] ; then
export PATH="/usr/local/clang6/bin:$PATH"
fi
Note: If you are using a shell other than bash you will need to add the above into the appropriate file, e.g. for zsh add to ~/.zshrc, as this was not implemented in the official installer.
I should have a few cycles to finish writing a new unofficial Rtools installer a bit later. See: https://github.com/coatless/r-macos-rtools/issues/7
Note: Alternatively, you can remove the paths individual with
sudo vi ~/.R/Makevars
Pressing I to enter insert mode, deleting lines with clang4 in the path, and then pressing ESC + :wq to write changes to file.

Answer 2

Never mind, this problem went away with version 0.8.600. Later, this problem appeared again when I upgraded to RcppArmadillo 0.9.100.5.0. Somehow I only got this error when building from source; I downloaded the binary manually from the CRAN website, and used R CMD INSTALL to install the prebuilt version, and it worked; somehow R doesn't seem to know that there is a binary available for the newest version.
I did install clang6 and modified .R/Makevars to use clang6, but the same problem persisted; probably something else caused the problem.