Running examples in 'auk-Ex.R' failed
The error most likely occurred in:

> ### Name: format_unmarked_occu
> ### Title: Format EBD data for occupancy modeling with 'unmarked'
> ### Aliases: format_unmarked_occu
> 
> ### ** Examples
> 
> # read and zero-fill the ebd data
> f_ebd <- system.file("extdata/zerofill-ex_ebd.txt", package = "auk")
> f_smpl <- system.file("extdata/zerofill-ex_sampling.txt", package = "auk")
> # data must be for a single species
> ebd_zf <- auk_zerofill(x = f_ebd, sampling_events = f_smpl,
+                        species = "Collared Kingfisher",
+                        collapse = TRUE)
> occ <- filter_repeat_visits(ebd_zf, n_days = 30)
> # format for unmarked
> # typically one would join in habitat covariates prior to this step
> occ_wide <- format_unmarked_occu(occ,
+                                  response = "species_observed",
+                                  site_covs = c("latitude", "longitude"),
+                                  obs_covs = c("effort_distance_km", 
+                                               "duration_minutes"))
> # create an unmarked object
> if (requireNamespace("unmarked", quietly = TRUE)) {
+   occ_um <- unmarked::formatWide(occ_wide, type = "unmarkedFrameOccu")
+   unmarked::summary(occ_um)
+ }
unmarkedFrame Object

47 sites
Maximum number of observations per site: 10 
Mean number of observations per site: 3.85 
Sites with at least one detection: 25 

Tabulation of y observations:
FALSE  TRUE  <NA> 
  129    52   289 

Site-level covariates:
    latitude       longitude    
 Min.   :1.206   Min.   :103.7  
 1st Qu.:1.315   1st Qu.:103.7  
 Median :1.351   Median :103.8  
 Mean   :1.348   Mean   :103.8  
 3rd Qu.:1.369   3rd Qu.:103.8  
 Max.   :1.446   Max.   :104.0  

Observation-level covariates:
 effort_distance_km duration_minutes
 Min.   : 0.100     Min.   :  1.00  
 1st Qu.: 0.200     1st Qu.: 15.00  
 Median : 1.000     Median : 30.00  
 Mean   : 1.584     Mean   : 67.06  
 3rd Qu.: 2.000     3rd Qu.: 86.25  
 Max.   :10.000     Max.   :480.00  
 NA's   :393        NA's   :392     
> 
> # this function can also be used for abundance modeling
> abd <- ebd_zf %>% 
+   # convert count to integer, drop records with no count
+   dplyr::mutate(observation_count = as.integer(observation_count)) %>% 
+   dplyr::filter(!is.na(observation_count)) %>% 
+   # filter to repeated visits
+   filter_repeat_visits(n_days = 30)
Error in nchar(xs) : 
  number of characters is not computable in "bytes" encoding, element 1
Calls: %>% ... mutate_cols -> withCallingHandlers -> <Anonymous> -> .Call
Execution halted