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

> ### Name: plot.optweight
> ### Title: Plot Dual Variables for Assessing Balance Constraints
> ### Aliases: plot.optweight plot.optweight.svy
> 
> ### ** Examples
> 
> library("cobalt")
> data("lalonde", package = "cobalt")
> 
> #Balancing covariates between treatment groups (binary)
> ow1 <- optweight(treat ~ age + educ + married +
+                 nodegree + re74, data = lalonde,
+                 tols = c(.1, .1, .1, .1, .1),
+                 estimand = "ATT")
> 
> summary(ow1) # Note the coefficient of variation
Summary of weights:

- Weight ranges:
        Min                                  Max
treated   1                   ||          1.0000
control   0 |---------------------------| 1.5946

- Units with 5 greatest weights by group:
                                           
              2      3      4      5      6
 treated      1      1      1      1      1
            604    599    589    572    569
 control 1.5946 1.5946 1.5946 1.5946 1.5946

        Coef of Var Mean Abs Dev
treated      0.0000       0.0000
control      0.5319       0.4619
overall      0.4446       0.3227

- Effective Sample Sizes:
           Control Treated
Unweighted 429.000     185
Weighted   334.408     185
>              # and effective sample size (ESS)
> 
> plot(ow1) # age has a low value, married is high
Error in namespaceExport(ns, exports) : 
  undefined exports: %s!=%, %s!==%, %s+%, %s<%, %s<=%, %s==%, %s===%, %s>%, %s>=%, %stri!=%, %stri!==%, %stri+%, %stri<%, %stri<=%, %stri==%, %stri===%, %stri>%, %stri>=%, stri_datetime_add<-, stri_sub<-, stri_subset<-, stri_subset_charclass<-, stri_subset_coll<-, stri_subset_fixed<-, stri_subset_regex<-, stri_c, stri_c_list, stri_cmp, stri_cmp_eq, stri_cmp_equiv, stri_cmp_ge, stri_cmp_gt, stri_cmp_le, stri_cmp_lt, stri_cmp_neq, stri_cmp_nequiv, stri_compare, stri_conv, stri_count, stri_count_boundaries, stri_count_charclass, stri_count_coll, stri_count_fixed, stri_count_regex, stri_count_words, stri_datetime_add, stri_datetime_create, stri_datetime_fields, stri_datetime_format, stri_datetime_fstr, stri_datetime_now, stri_datetime_parse, stri_datetime_symbols, stri_detect, stri_detect_charclass, stri_detect_coll, stri_detect_fixed, stri_detect_regex, stri_dup, stri_duplicated, stri_duplicated_any, stri_enc_detect, stri_enc_detect2, stri_enc_fromutf32, stri_enc_get, stri_enc_inf
Calls: <Anonymous> ... tryCatch -> tryCatchList -> tryCatchOne -> <Anonymous>
Execution halted