• R: 4.1.2
• OS: ArchLinux
• gcc: 11.2.0

I have installed the r-rcpp, but it still told me that Rcpp.h: No such file or directory

Code should be placed in three backticks as shown below

* installing *source* package ‘Rgin’ ...
** using staged installation
** libs
gcc -I"/usr/include/R/" -DNDEBUG  -I'/usr/lib/R/library/RcppEigen/include' -I/usr/local/include   -fpic  -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security         -fstack-clash-protection -fcf-protection -flto  -c Rgin-init.c -o Rgin-init.o
g++ -std=gnu++14 -I"/usr/include/R/" -DNDEBUG  -I'/usr/lib/R/library/RcppEigen/include' -I/usr/local/include  -std=c++11 -fopenmp -D_USE_KNETFILE -D_FILE_OFFSET_BITS=64 -U_FORTIFY_SOURCE -DBGZF_CACHE -DAS_GINLIB -DAS_RGINLIB -I./include -I./lib `/usr/lib64/R/bin/Rscript -e "Rcpp:::CxxFlags()"` -lz -fpic  -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security         -fstack-clash-protection -fcf-protection -Wp,-D_GLIBCXX_ASSERTIONS -flto  -c src/feature_selection/feature_selector.cc -o src/feature_selection/feature_selector.o
g++ -std=gnu++14 -I"/usr/include/R/" -DNDEBUG  -I'/usr/lib/R/library/RcppEigen/include' -I/usr/local/include  -std=c++11 -fopenmp -D_USE_KNETFILE -D_FILE_OFFSET_BITS=64 -U_FORTIFY_SOURCE -DBGZF_CACHE -DAS_GINLIB -DAS_RGINLIB -I./include -I./lib `/usr/lib64/R/bin/Rscript -e "Rcpp:::CxxFlags()"` -lz -fpic  -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security         -fstack-clash-protection -fcf-protection -Wp,-D_GLIBCXX_ASSERTIONS -flto  -c src/feature_selection/scones.cc -o src/feature_selection/scones.o
In file included from ./include/gin/feature_selection/scones.h:8,
                 from src/feature_selection/scones.cc:5:
./include/gin/globals.h:60:10: fatal error: Rcpp.h: No such file or directory
   60 | #include "Rcpp.h"
      |          ^~~~~~~~
compilation terminated.
make: *** [/usr/lib64/R/etc/Makeconf:175: src/feature_selection/scones.o] Error 1
make: *** Waiting for unfinished jobs....
In file included from ./include/gin/feature_selection/scones.h:8,
                 from src/feature_selection/feature_selector.cc:9:
./include/gin/globals.h:60:10: fatal error: Rcpp.h: No such file or directory
   60 | #include "Rcpp.h"
      |          ^~~~~~~~
compilation terminated.
make: *** [/usr/lib64/R/etc/Makeconf:175: src/feature_selection/feature_selector.o] Error 1
ERROR: compilation failed for package ‘Rgin’
* removing ‘/build/r-rgin/src/Rgin’
* restoring previous ‘/build/r-rgin/src/Rgin’

Still not you.