[R-SIG-Mac] Announcement: R-devel "sonoma-arm64" Mac builds

[Simon Urbanek]

> On 14/12/2025, at 12:03 PM, Jeroen Ooms <jeroenooms using gmail.com> wrote:
> 
> On Sat, Dec 13, 2025 at 10:39 PM Simon Urbanek
> <simon.urbanek using r-project.org> wrote:
>> 
>> 
>> 
>>> On 14/12/2025, at 11:24 AM, Jeroen Ooms <jeroenooms using gmail.com> wrote:
>>> 
>>> On Fri, Dec 12, 2025 at 3:20 AM Simon Urbanek
>>> <simon.urbanek using r-project.org> wrote:
>>> 
>>>> The goal is to remove the existing big-sur-arm64 R-devel binaries in favor of the sonoma-arm64 R-devel build. Since we are still far away from the R-devel release, all this is considered experimental and may change in the future (possibly Fortran upgrade is in the cards), but given that this is not a minor change, I want to give others the opportunity to test the new setup and comment as appropriate.
>>> 
>>> Thanks. Some quick observations:
>>> 
>>> The x86_64 build of r-devel on https://mac.r-project.org/ is almost 2 months old?
>>> 
>> 
>> Should be fixed now.
>> 
>> 
>>> On arm64, using the latest R-devel-arm64.pkg on a machine with macOS 15 and Xcode_16.2, I get the following error for all packages with compiled C code:
>>> 
>>> error: invalid value 'gnu23' in '-std=gnu23'
>>> note: use 'c2x' for 'Working Draft for ISO C2x' standard
>>> note: use 'gnu2x' for 'Working Draft for ISO C2x with GNU extensions' standard
>>> 
>> 
>> 
>> That is expected, you'll need at least Xcode 16.3 since 16.2 is LLVM 17 while 16.3 is LLVM 19 which, as has been discussed at length, was a big breaking jump. As noted, what is actually used is Xcode 26.x so that would be recommended (albeit not required).
> 
> The reason we were using 16.2 is that newer xcode versions still do
> not seem to work with the libomp.dylib included with base R. Has
> libomp.dylib been updated yet?


Yes, it matches the Xcode - as noted:


> On 12/12/2025, at 4:25 PM, Simon Urbanek <simon.urbanek using R-project.org> wrote:
> 
>> On 12 Dec 2025, at 08:26, Jeroen Ooms <jeroenooms using gmail.com> wrote:
>> [...]
>> Also It would be interesting to know which version of libomp.dylib will be included with R-macos 4.6 :)
>> 
> 
> LLVM 19.1.5 to match current Xcode 26.x, i.e. https://mac.r-project.org/openmp/openmp-19.1.5-darwin20-Release.tar.gz
> 



Again, that was the point of the tool upgrade :).



> According to otool it is the same version as before?
> 


otool shows the API version as declared by Intel OpenMP, but the LLVM team has never updated it despite breaking changes, unfortunately :/. It's really annoying since it means it is very hard to determine which LLVM it came from - even internally all of the them declare the same version 5.0.20140926 and API version 5.0.201611 - both being almost 10 years out of date.

Cheers,
Simon



>  otool -L lib/libomp.dylib
>     /Library/Frameworks/R.framework/Versions/4.6/Resources/lib/libomp.dylib
> (compatibility version 5.0.0, current version 5.0.0)
>     /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
> version 1292.100.5)
>