fast install package during development with multiarch

Question

I'm working on a package "xyz" that uses Rcpp with several cpp files. When I'm only updating the R code, I would like to run R CMD INSTALL xyz on the package directory without having to recompile all the shared libraries that haven't changed. That works fine if I specify the --no-multiarch flag: the source directory src gets populated the first time with the compiled objects, and if the sources don't change they are re-used the next time. With multiarch on, however, R decides to make two copies of src, src-i386 and src-x86_64. It seems to confuse R CMD INSTALL which always re-runs all the compilation. Is there any workaround?

(I'm aware that there are alternative ways, e.g. devtools::load_all, but I'd rather stick to R CM INSTALL if possible).

The platform is MacOS 10.7, and I have the latest version of R.

Answer 1

I have a partial answer for you. One really easy for speed-up is provided by using ccache which you can enable for all R compilation (e.g. via R CMD whatever thereby also getting inline, attributes, RStudio use, ...) globally through .R/Makevars:

edd@max:~$ tail -10 .R/Makevars

VER=4.6
CC=ccache gcc-$(VER)
CXX=ccache g++-$(VER)
SHLIB_CXXLD=g++-$(VER)
FC=ccache gfortran
F77=ccache gfortran
MAKE=make -j8

edd@max:~$ 

It takes care of all caching of compilation units.

Now, that does not "explicitly" address the --no-multiarch aspect which I don;t play much with that as we are still mostly 'single arch' on Linux. This will change, eventually, but hasn't yet. Yet I suspect but by letting the compiler decide the caching you too will get the net effect.

Other aspects can be controlled too, eg ~/.R/check.Renviron can be used to turn certain tests on or off. I tend to keep'em all on -- better to waste a few seconds here than to get a nastygram from Vienna.