[Rd] Update on MinGW-w64 builds for 64-bit Windows

[Prof Brian Ripley]

An update to the announcement at
https://stat.ethz.ch/pipermail/r-devel/2010-January/056301.html

We now have daily builds of snapshots of R-devel for 64-bit Windows
available at http://cran.r-project.org/bin/windows64/contrib/ . 
Tcl/Tk support is now provided.

There is a repository of binary packages available, selected by
options(pkgType="win64.binary"), at CRAN and CRANextras: currently we
can build about 2000 packages.  The win-builder service has an option
to build and test packages under the current R-devel snapshot, and
logs of the builds for the repository are available as part of the
CRAN daily check at
http://cran.r-project.org/web/checks/check_summary.html (but note that
some of the failures are available on CRANextras).  The default 
remains to build packages from sources.

The main reason that packages have failed to build are unresolved 
dependencies on either other R packages or external software. 
Pre-built 64-bit DLLs of common Open Source libraries are much harder 
to find than 32-bit ones and we have not put in the effort that we 
have over the years for 32-bit Windows.  Bioconductor binary packages 
are not available (but that project has plans to build them in due 
course).

Package maintainers who ignored the advice not to write Makefiles (but
use Makevars) will find that chickens have come home to roost: such
packages almost certainly will not install.  Including

include $(R_HOME)/etc/Makeconf

and using macros such as $(CC), $(AR) and $(DLLTOOL) or (better) the
rules in Makeconf often does enable Makefile[.win] to be used.

Brian Ripley and Uwe Ligges

-- 
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