[R-SIG-Mac] M1 mid-January update

[Prof Brian Ripley]

For native builds - nothing to report for x86_64 builds running under 
Rosetta which almost all the time 'just work' (and work fast).

The goal remains to release a native binary distribution with R 4.1.0 ca 
April: all but the intrepid are advised to use x86_64 until then.

- There is an experimental R-devel build of the R framework at 
https://mac.r-project.org/ .  That page reports 'failed' but usually the 
framework is complete.

- R.app will need to be partially re-written as it uses Objective C 
features which are no longer supported in Xcode 12.  (I guess this is 
why the page is reporting a failure.)

- There are most parts of a toolchain and a Fortran compiler at 
https://mac.r-project.org/libs-arm64/ (not the earlier versions at 
libs-arm).  These install into /opt/R/arm64, and the R-admin manual has 
been re-written to reflect that and point out some pitfalls.

- Binary packages are planned but the vast majority of packages install 
from source.  I currently have 240 CRAN check failures with 35 failing 
to install and 98 others requiring those (or BioC ones).  If you are 
interested in a particular package, 
https://www.stats.ox.ac.uk/pub/bdr/M1mac/ has recent logs for those 
failing directly, listed as 'additional issues' on their CRAN check pages.

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