Problem with tidyr in R 3.2.4, works fine in 3.2.3
library(tidyr); library(dplyr); ##
## Attaching package: 'dplyr'
try(expand(mtcars, nesting(vs, cyl)))
devtools::session_info()## Session info --------------------------------------------------------------
## setting value
## version R version 3.2.4 Patched (2016-03-28 r70414)
## system x86_64, mingw32
## ui RStudio (0.99.893)
## language (EN)
## collate English_Australia.1252
## tz Australia/Hobart
## date 2016-04-05
## Packages ------------------------------------------------------------------
## package * version date source
## assertthat 0.1 2013-12-06 CRAN (R 3.2.4)
## DBI 0.3.1 2014-09-24 CRAN (R 3.2.4)
## devtools * 1.10.0 2016-01-23 CRAN (R 3.2.4)
## digest 0.6.9 2016-01-08 CRAN (R 3.2.4)
## dplyr * 0.4.3.9001 2016-03-23 Github (hadley/dplyr@06b1b20)
## evaluate 0.8.3 2016-03-05 CRAN (R 3.2.4)
## formatR 1.3 2016-03-05 CRAN (R 3.2.4)
## htmltools 0.3.5 2016-03-21 CRAN (R 3.2.4)
## knitr 1.12.3 2016-01-22 CRAN (R 3.2.4)
## lazyeval 0.1.10.9000 2016-03-23 Github (hadley/lazyeval@f7c54d1)
## magrittr 1.5 2014-11-22 CRAN (R 3.2.4)
## memoise 1.0.0 2016-01-29 CRAN (R 3.2.4)
## R6 2.1.2 2016-01-26 CRAN (R 3.2.4)
## Rcpp 0.12.4 2016-03-26 CRAN (R 3.2.4)
## rmarkdown 0.9.5 2016-02-22 CRAN (R 3.2.4)
## stringi 1.0-1 2015-10-22 CRAN (R 3.2.3)
## stringr 1.0.0 2015-04-30 CRAN (R 3.2.4)
## tidyr * 0.4.1 2016-02-05 CRAN (R 3.2.4)
## yaml 2.1.13 2014-06-12 CRAN (R 3.2.4)