[R-SIG-Mac] Choosing between Snow Leopard and Mavericks builds

[Prof Brian Ripley]

I've noticed some confusion about which CRAN installer package to use, 
and even reluctance to update to 3.1.0.  So some pointers for Mavericks 
users

1) AFAIK no users are going to be worse off using the Snow Leopard build 
of 3.1.0 rather than the only (Snow Leopard) build of 3.0.x.

2) The Mavericks build has support for C++11-using packages (there are 
currently less than a handful) and some performance improvements from 
its later compilers (and in rare cases these are large).

3) If you rely on binary packages with are not available for the 
Mavericks build, install the Snow Leopard one.  Currently that includes 
CRAN packages rgdal and rjags and all the BioC packages.

4) If you install packages from source, you will be most likely better 
off with the Mavericks build.

5) The two builds need different Fortran compilers installed: you can 
have both compilers at once.  The details are at 
http://cran.r-project.org/doc/manuals/r-release/R-admin.html#OS-X .  As 
far as I know a Fortran compiler is only needed if you install packages 
from sources.

Some of the Mavericks binary packages are missing for good reason.  The 
C++ binary interface for the Xcode 5.x compilers in Mavericks is 
completely different, so external software has to be compiled with those 
compilers.  This affects CRAN packages

RQuantlib RProtoBuf RVowalWabbit rgdal rjags rzmq

Most of these can be gotten to work (see the results labelled 
r-devel-osx-x86_64-clang at 
http://cran.r-project.org/web/checks/check_summary.html) if compiling 
from sources.  There are packages with badly-written C++ which do not 
compile under Mavericks, but as we have been chasing the CRAN 
maintainers for a few months there are very few left (the main example 
is BioC's package mzR).

We had expected that by this time Mavericks users would be in a 
majority, but it seems the proportion is in the 40s (%).  Thus for R 
3.1.0 most of the effort has gone into the Snow Leopard build: expect 
that to change by R 3.2.0 in a year's time.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595