A bug-fix release 0.3.2.1.2 is of RcppEigen is now on CRAN and in Debian. It contains a short upstream patch by Gaek Guennebaud for the UBSAN warnings that were flagged at CRAN (from a rather harmless cpu-id comparison). The
Courtesy of CRANberries, there are diffstat reports for the most recent release. Questions, comments etc about RcppEigen should go to the rcpp-devel mailing list off the R-Forge page.
Changes in RcppEigen version 0.3.2.1.2 (2014-05-05)
Applied upstream patch to not trigger g++ UBSAN warning on the cpu id comparison, with thanks to Gael Guennebaud for the patch