* installing *source* package ‘ggtern’ ...
** this is package ‘ggtern’ version ‘3.5.0’
** package ‘ggtern’ successfully unpacked and MD5 sums checked
** using staged installation
** R
** data
** demo
** inst
** byte-compile and prepare package for lazy loading
Error in get(x, envir = ns, inherits = FALSE) : 
  object 'is.zero' not found
Error: unable to load R code in package ‘ggtern’
Execution halted
ERROR: lazy loading failed for package ‘ggtern’
* removing ‘/data/gannet/ripley/R/packages/tests-devel/ggtern.Rcheck/ggtern’