As R-3.3.0 will use gcc 4.9.3 with full support for C11, perhaps CXX1XSTD = -std=c++0x should be replaced by CXX1XSTD = -std=c++11 there? Most of the time, packages build from .R/Makevars, but sometimes, and I don't know why, they default to the fixed/etc. Thank you, Avi