Failed to build R package. #5894
Description
After #5871 I can't build R package on my local machine with link time error:
/usr/bin/ld: ../../R-package/CMakeFiles/xgboost-r.dir/src/init.c.o: in function `R_init_xgboost':
/home/fis/Workspace/XGBoost/xgboost/R-package/src/init.c:83: undefined reference to `R_registerRoutines'
/usr/bin/ld: /home/fis/Workspace/XGBoost/xgboost/R-package/src/init.c:84: undefined reference to `R_useDynamicSymbols'
/usr/bin/ld: ../../R-package/CMakeFiles/xgboost-r.dir/src/xgboost_R.cc.o: in function `XGCheckNullPtr_R':
/home/fis/Workspace/XGBoost/xgboost/R-package/src/xgboost_R.cc:41: undefined reference to `R_ExternalPtrAddr'
/usr/bin/ld: /home/fis/Workspace/XGBoost/xgboost/R-package/src/xgboost_R.cc:41: undefined reference to `Rf_ScalarLogical'
/usr/bin/ld: ../../R-package/CMakeFiles/xgboost-r.dir/src/xgboost_R.cc.o: in function `_DMatrixFinalizer(SEXPREC*)':
...
R: 3.6.1
CMake: 3.13.4
GCC: gcc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008