[Rd] Advice debugging M1Mac check errors

[Prof Brian Ripley]

On 04/02/2024 19:41, Holger Hoefling wrote:
> Hi,
> 
> I wanted to ask if people have good advice on how to debug M1Mac package
> check errors when you don´t have a Mac? Is a cloud machine the best option
> or is there something else?

I presumed this was about a CRAN package, possibly hdf5r which has a 
R-devel-only warning from the Apple clang compiler.  And that is not a 
'check error' and not something to 'debug'.

The original poster had errors for his package flsa until yesterday on 
fedora-clang and M1mac, which were compilation errors with recent LLVM 
and Apple compilers.  Again, not really something to 'debug' -- the 
compiler messages were clear and the CRAN notification contained advice 
on where in our manual to look this up.

The mac-builder service offers checks for R 4.3.0, the 'development' 
option being (last time I tried) the same as the 'release' option. (When 
I asked, Simon said that 'development' checks were only available in the 
run up to a x.y.0 when he starts package building and checks for R-devel.)


We were left to guess, but I doubt this has to do with the lack of 
'extended precision' nor long doubles longer than doubles on arm64 
macOS.  And issues with that are rather rare (much rarer than numerical 
issues for non-reference x86_64 BLAS/LAPACKs).  Of the 20,300 CRAN 
packages just 18 have M1mac-specific errors, none obviously from 
numerical inaccuracy.  A quick look back suggests we get about 20 a year 
with M1mac numerical issues, about half of which were mirrored on the 
x86_64 'noLD' checks.

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