Since R 4.0 data.table can no longer can use OpenMP if installed as a binary from CRAN. The message upon loading the package is: "data.table 1.12.8 using 1 threads (see ?getDTthreads). Latest news: r-datatable.com"
However, it is possible to install from source following the guide provided on https://github.com/Rdatatable/data.table/wiki/Installation. I followed the guide and the compilation did succeed, but produced a ton of compiler warnings of the type below.
> install.packages("data.table", type = "source")
trying URL 'https://mirror.ibcp.fr/pub/CRAN/src/contrib/data.table_1.12.8.tar.gz'
Content type 'application/x-gzip' length 4948391 bytes (4.7 MB)
==================================================
downloaded 4.7 MB
* installing *source* package ‘data.table’ ...
** package ‘data.table’ successfully unpacked and MD5 sums checked
** using staged installation
*** pkg-config is not installed.
*** Compilation will now be attempted and if it works you can ignore this message. However,
*** if compilation fails, try 'locate zlib.h zconf.h' and ensure the zlib development library
*** is installed :
*** deb: zlib1g-dev (Debian, Ubuntu, ...)
*** rpm: zlib-devel (Fedora, EPEL, ...)
*** brew: zlib (OSX)
*** Note that zlib is required to compile R itself so you may find the advice in the R-admin
*** guide helpful regarding zlib. On Debian/Ubuntu, zlib1g-dev is a dependency of r-base as
*** shown by 'apt-cache showsrc r-base | grep ^Build-Depends | grep zlib', and therefore
*** 'sudo apt-get build-dep r-base' should be sufficient too.
*** To silence this message, please ensure that :
*** 1) 'pkg-config --exists zlib' succeeds (i.e. $? -eq 0)
*** 2) 'pkg-config --libs zlib' contains -lz
*** Compilation will now be attempted ...
** libs
/usr/local/bin/clang -fopenmp -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/usr/local/opt/gettext/include -I/usr/local/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -fPIC -g -O3 -Wall -pedantic -std=gnu99 -mtune=native -pipe -c assign.c -o assign.o
In file included from assign.c:1:
In file included from ./data.table.h:1:
In file included from ./dt_stdio.h:30:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/stdio.h:64:
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/_stdio.h:137:9: warning: type nullability specifier '_Nullable' is a Clang extension [-Wnullability-extension]
int (* _Nullable _close)(void *);
^
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/_stdio.h:93:16: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
unsigned char *_base;
^
...
...
...
212 warnings generated.
ld: warning: directory not found for option '-L/usr/local/opt/gettext/lib'
installing to /Library/Frameworks/R.framework/Versions/4.0/Resources/library/00LOCK-data.table/00new/data.table/libs
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded from temporary location
** checking absolute paths in shared objects and dynamic libraries
** testing if installed package can be loaded from final location
** testing if installed package keeps a record of temporary installation path
* DONE (data.table)
I am not an IT specialist, standard compiling from source following the instructions is my limit and the rest is quite beyond me. The complete output of the compilation is under this link.
So I would like to understand the following:
Are these warnings critical? Will all these warnings affect the performance of the package?
Many thanks, for the clarification.
The sessionInfo() is below:
sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Catalina 10.15.5
Matrix products: default
BLAS: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib
locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
attached base packages:
[1] stats graphics grDevices utils datasets methods base
loaded via a namespace (and not attached):
[1] compiler_4.0.2 tools_4.0.2
