On Jan 3, 2026, at 9:43?PM, Simon Urbanek <simon.urbanek at R-project.org> wrote:
Naresh,
as for the original problem, just re-install the package binary from CRAN (see [1], i.e., just run install.packages("data.table",repos="https://mac.r-project.org")).
As for your secondary problem (which should be irrelevant by now since you can get the right binary from CRAN), you have mismatching Xcode and OpenMP versions. I suspect you are using Xocde/CLT > 16.2 which is incompatible with the clang 17 run-time (see the note on the OpenMP page). So if you really want to compile it from sources, the two options you have are a) install Xcode/CLT 16.2 (which uses clang 17) or b) use OpenMP from clang 19. For the latter, however, you may need some work since that run-time is incompatible with the libomp shipped with R so you may need to modify the flags (see the note in the flags section of the OpenMP page), but I'm not 100% sure if data.table supports that (or you can replace the R run-time with the clang 19 run-time if you don't use any packages that link to it). Again, it's much easier to install the updated CRAN binary.
Cheers,
Simon
[1] - https://stat.ethz.ch/pipermail/r-sig-mac/2026-January/015314.html
On 30/12/2025, at 11:55, Naresh Gurbuxani <naresh_gurbuxani at hotmail.com> wrote:
I should have posted this here.
Sent from my iPhone
Begin forwarded message:
From: Naresh Gurbuxani <naresh_gurbuxani at hotmail.com>
Date: December 29, 2025 at 12:02:10?PM EST
To: r-help at r-project.org
Subject: [R] data.table does not find openmp support
?
On my Intel Mac, with R 4.4, data.table worked with openmp support.
After installing R 4.5, I reinstalled data.table using
install.packages("data.table"). Installation went smoothly, but
data.table did not detect openmp support. I removed data.table, then
reinstalled using install.packages("data.table", type = "source"). Now
data.table install has non-zero exit status.
Following instructions at https://mac.r-project.org/openmp/, I installed
Open MP support by running on command line
curl -O https://mac.r-project.org/openmp/openmp-17.0.6-darwin20-Release.tar.gz
sudo tar fvxz openmp-17.0.6-darwin20-Release.tar.gz -C /
Below is information from my R session:
sessionInfo()
R version 4.5.2 (2025-10-31)
Platform: x86_64-apple-darwin20
Running under: macOS Sequoia 15.7.3
Matrix products: default
BLAS: /Library/Frameworks/R.framework/Versions/4.5-x86_64/Resources/lib/libRblas.0.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.5-x86_64/Resources/lib/libRlapack.dylib; LAPACK version 3.12.1
locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
time zone: America/New_York
tzcode source: internal
attached base packages:
[1] stats graphics utils datasets grDevices methods base
other attached packages:
[1] lattice_0.22-7
loaded via a namespace (and not attached):
[1] compiler_4.5.2 tools_4.5.2 grid_4.5.2
system("gfortran --version")
GNU Fortran (GCC) 14.2.0
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
system("xcode-select -version")
xcode-select version 2410.
system("gcc --version")
Apple clang version 17.0.0 (clang-1700.6.3.2)
Target: x86_64-apple-darwin24.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
install.packages("data.table", lib = .libPaths()[2], type = "source")
trying URL 'https://cran.r-project.org/src/contrib/data.table_1.18.0.tar.gz'
Content type 'application/x-gzip' length 6020932 bytes (5.7 MB)
==================================================
downloaded 5.7 MB
* installing *source* package ?data.table? ...
** this is package ?data.table? version ?1.18.0?
** package ?data.table? successfully unpacked and MD5 sums checked
** using staged installation
zlib 1.3.1 is available ok
* checking if R installation supports OpenMP with "-Xclang -fopenmp" ... yes
** libs
using C compiler: ?Apple clang version 17.0.0 (clang-1700.6.3.2)?
using SDK: ?MacOSX26.2.sdk?
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c assign.c -o assign.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c between.c -o between.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c bmerge.c -o bmerge.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c chmatch.c -o chmatch.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c cj.c -o cj.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c coalesce.c -o coalesce.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c dogroups.c -o dogroups.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fastmean.c -o fastmean.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fcast.c -o fcast.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fifelse.c -o fifelse.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fmelt.c -o fmelt.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c forder.c -o forder.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c frank.c -o frank.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fread.c -o fread.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c freadR.c -o freadR.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c froll.c -o froll.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c frollR.c -o frollR.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c frolladaptive.c -o frolladaptive.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c frollapply.c -o frollapply.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fsort.c -o fsort.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fwrite.c -o fwrite.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c fwriteR.c -o fwriteR.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c gsumm.c -o gsumm.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c hash.c -o hash.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c idatetime.c -o idatetime.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c ijoin.c -o ijoin.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c init.c -o init.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c inrange.c -o inrange.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c mergelist.c -o mergelist.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c nafill.c -o nafill.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c negate.c -o negate.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c nqrecreateindices.c -o nqrecreateindices.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c openmp-utils.c -o openmp-utils.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c programming.c -o programming.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c quickselect.c -o quickselect.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c rbindlist.c -o rbindlist.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c reorder.c -o reorder.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c shellsort.c -o shellsort.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c shift.c -o shift.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c snprintf.c -o snprintf.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c subset.c -o subset.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c transpose.c -o transpose.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c types.c -o types.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c uniqlist.c -o uniqlist.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c utils.c -o utils.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c vecseq.c -o vecseq.o
clang -arch x86_64 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I/opt/R/x86_64/include -Xclang -fopenmp -I/opt/local/include -fPIC -falign-functions=64 -Wall -g -O2 -c wrappers.c -o wrappers.o
clang -arch x86_64 -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -L/Library/Frameworks/R.framework/Resources/lib -L/opt/R/x86_64/lib -o data.table.so assign.o between.o bmerge.o chmatch.o cj.o coalesce.o dogroups.o fastmean.o fcast.o fifelse.o fmelt.o forder.o frank.o fread.o freadR.o froll.o frollR.o frolladaptive.o frollapply.o fsort.o fwrite.o fwriteR.o gsumm.o hash.o idatetime.o ijoin.o init.o inrange.o mergelist.o nafill.o negate.o nqrecreateindices.o openmp-utils.o programming.o quickselect.o rbindlist.o reorder.o shellsort.o shift.o snprintf.o subset.o transpose.o types.o uniqlist.o utils.o vecseq.o wrappers.o -lomp -L/opt/local/lib -lz -F/Library/Frameworks/R.framework/.. -framework R
PKG_CFLAGS = -Xclang -fopenmp -I/opt/local/include
PKG_LIBS = -lomp -L/opt/local/lib -lz
if [ "data.table.so" != "data_table.so" ]; then mv data.table.so data_table.so; fi
if [ "" != "Windows_NT" ] && [ `uname -s` = 'Darwin' ]; then install_name_tool -id data_table.so data_table.so; fi
installing to /Library/Frameworks/R.framework/Versions/4.5-x86_64/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
Error: package or namespace load failed for ?data.table? in dyn.load(file, DLLpath = DLLpath, ...):
unable to load shared object '/Library/Frameworks/R.framework/Versions/4.5-x86_64/Resources/library/00LOCK-data.table/00new/data.table/libs/data_table.so':
dlopen(/Library/Frameworks/R.framework/Versions/4.5-x86_64/Resources/library/00LOCK-data.table/00new/data.table/libs/data_table.so, 0x0006): symbol not found in flat namespace '___kmpc_dispatch_deinit'
Error: loading failed
Execution halted
ERROR: loading failed
* removing ?/Library/Frameworks/R.framework/Versions/4.5-x86_64/Resources/library/data.table?
The downloaded source packages are in
?/private/var/folders/d5/sbs6108j6qd9jw7g652bm9sr0000gn/T/RtmpqcFVH3/downloaded_packages?
Warning message:
In install.packages("data.table", lib = .libPaths()[2], type = "source") :
installation of package ?data.table? had non-zero exit status