[R-SIG-Mac] r-sig-mac maybe from r-project.org - "You can’t open the application “R” because this application is not supported on this Mac"

[Prof Brian Ripley]

On 17/07/2021 21:38, Duncan Murdoch wrote:
> On 17/07/2021 3:39 a.m., Lindsay Foreman wrote:
>> To whom it may concern,
>>
>> I am so sorry for being such a dunce.  I have been trying and trying 
>> to get the R App to work on my MacBook Air running Big Sur V11.4, and 
>> am just not making any progress.  It says that the package I have 
>> downloaded below should have all the elements I need including the R 
>> app GUI.  I get this error message "You can’t open the application “R” 
>> because this application is not supported on this Mac"., are you able 
>> to help please?
> 
> Is that an Intel or M1 MacBook?  If it's an Intel one, you don't want 
> the arm64 download, you want
> 
> https://cran.r-project.org/bin/macosx/base/R-4.1.0.pkg
> 
> It is listed on the web site as "High Sierra and higher", so it should 
> work on Big Sur, but only if you have an Intel chip.

Yes, it works on Intel Big Sur.  Actually it works perfectly well on 
arm64 (aka M1) cpus, as documented in the R-admin manual and on 
https://cran.r-project.org/bin/macosx/ .

For those with arm64 Macs, the current pros and cons of the arm64 build are

Pro:
- It is usually faster, median 1.4x on CRAN packages but in some cases 
much more so.

- There have been very occasional Intel binary packages where Rosetta 
emulation does not work (and the arm64 binary package did).

Cons:
- Less accuracy as there are no long doubles.  That has surprisingly 
little impact, in part because CRAN packages have long been checked 
without long doubles.  But people who test sum(p) == 1 are more likely 
to be caught out ....

- Fewer binary packages available, notably not from Bioconductor and 
hence CRAN packages requiring those from Bioconductor.

- In the vast majority of cases compiling packages from source will work 
(if sometimes a little trickier), but a handful of packages require 
Intel CPUs.  I have about 30 more CRAN packages failing their checks 
that for Intel builds, and about 40 than on Linux.

- Less stable.  This is as much the OS as R, with resource (e.g. RAM) 
shortages leading to hangs (of R or the whole machine) much more often 
than on an Intel Mac.  In fairly limited testing this happens more with 
the arm64 build than using the Intel build on my M1 Mac.

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