Just FYI Rcpp 0.8.3 itself didn't even build on OS X or Solaris according to
'Check Results' page on CRAN -- so we have some work to do there.
Windows did build so that would put the blame back onto your code.
Unfortunately, debugging (templated) C++ that doesn't work is not the most
straightf
Apparently I have gotten too fancy in writing a templated function to
apply a permutation to Rcpp::Vector classes. The templates are at the
end of lme4a/src/MatrixNs.h which can be obtained from R-forge under
the lme4 project. One of them is
class Permutation {
Rcpp::IntegerVector d_
