[R-SIG-Mac] vecLib-based BLAS not working with R 4.5.0

[Prof Brian Ripley]

On 15/04/2025 11:59, Ulrich KELLER wrote:
> Symlinking the vecLib-based BLAS no longer seems to work with R 4.5.0. After running `ln -sf libRblas.vecLib.dylib libRblas.dylib`, R fails to load the stats package:
> 
> ```
> During startup - Warning message:
> package ‘stats’ in options("defaultPackages") was not found
>> library(stats)
> Error: package or namespace load failed for ‘stats’ in dyn.load(file, DLLpath = DLLpath, ...):
>   unable to load shared object '/Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library/stats/libs/stats.so':
>    dlopen(/Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library/stats/libs/stats.so, 0x0006): Symbol not found: _dgemmtr_
>    Referenced from: <28799065-89DC-362D-9F05-042D50E7824C> /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRlapack.dylib
>    Expected in:     <BA0E9688-AFD2-34E6-A54F-3B08D084074A> /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRblas.vecLib.dylib
> ```
> 
> Switching back to the default BLAS fixes the problem. In R 4.4.3, which I also still have installed through rig, the vecLib BLAS works fine.

This is covered in NEWS (and in detail in the R-admin manual).  See in 
particular the NEWS section 'BLAS and LAPACK:'.

It seems no one who cares about this tested the nightly builds (and I 
believe using OpenBLAS, which is complete and is documented, is to be 
preferred).  Ideally Dr Urbanek would add the missing routines to 
libRblas.vecLib.dylib: he does not publicise how he builds that.  Or R 
could be built with --with-2025blas.

-- 
Brian D. Ripley,                  ripley using stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford