Running examples in ‘tibbletime-Ex.R’ failed
The error most likely occurred in:

> ### Name: collapse_index
> ### Title: Collapse an index vector so that all observations in an interval
> ###   share the same date
> ### Aliases: collapse_index
> 
> ### ** Examples
> 
> 
> # Basic functionality -------------------------------------------------------
> 
> # Facebook stock prices
> data(FB)
> FB <- as_tbl_time(FB, date)
> 
> # Collapse to weekly dates
> dplyr::mutate(FB, date = collapse_index(date, "weekly"))
# A time tibble: 1,008 x 8
# Index: date
   symbol date        open  high   low close    volume adjusted
   <chr>  <date>     <dbl> <dbl> <dbl> <dbl>     <dbl>    <dbl>
 1 FB     2013-01-04  27.4  28.2  27.4  28    69846400     28  
 2 FB     2013-01-04  27.9  28.5  27.6  27.8  63140600     27.8
 3 FB     2013-01-04  28.0  28.9  27.8  28.8  72715400     28.8
 4 FB     2013-01-11  28.7  29.8  28.6  29.4  83781800     29.4
 5 FB     2013-01-11  29.5  29.6  28.9  29.1  45871300     29.1
 6 FB     2013-01-11  29.7  30.6  29.5  30.6 104787700     30.6
 7 FB     2013-01-11  30.6  31.5  30.3  31.3  95316400     31.3
 8 FB     2013-01-11  31.3  32.0  31.1  31.7  89598000     31.7
 9 FB     2013-01-18  32.1  32.2  30.6  31.0  98892800     31.0
10 FB     2013-01-18  30.6  31.7  29.9  30.1 173242600     30.1
# … with 998 more rows
> 
> # A common workflow is to group on the new date column
> # to perform a time based summary
> FB %>%
+   dplyr::mutate(date = collapse_index(date, "yearly")) %>%
+   dplyr::group_by(date) %>%
+   dplyr::summarise_if(is.numeric, mean)
# A time tibble: 4 x 7
# Index: date
  date        open  high   low close    volume adjusted
  <date>     <dbl> <dbl> <dbl> <dbl>     <dbl>    <dbl>
1 2013-12-31  35.5  36.0  34.9  35.5 60091994.     35.5
2 2014-12-31  68.8  69.6  67.8  68.8 47530552.     68.8
3 2015-12-31  88.7  89.7  87.8  88.8 26955191.     88.8
4 2016-12-30 117.  118.  116.  117.  25453798.    117. 
> 
> # You can also assign the result to a separate column and use that
> # to nest on, allowing for 'period nests' that keep the
> # original dates in the nested tibbles.
> FB %>%
+   dplyr::mutate(nest_date = collapse_index(date, "2 year")) %>%
+   dplyr::group_by(nest_date) %>%
+   tidyr::nest()
Error in !.key : invalid argument type
Calls: %>% ... <Anonymous> -> nest.grouped_df -> check_key -> is_missing
Execution halted